diff --git a/src/cst/Transaction.ts b/src/cst/Transaction.ts
index 187bcaaf..d6c3cc82 100644
--- a/src/cst/Transaction.ts
+++ b/src/cst/Transaction.ts
@@ -1,11 +1,12 @@
 import { BaseNode, Keyword } from "./Base";
-import { Identifier } from "./Expr";
+import { Identifier, ListExpr } from "./Expr";
 
 export type AllTransactionNodes =
   | AllTransactionStatements
   | RollbackToSavepoint
   | TransactionChainClause
-  | TransactionNoChainClause;
+  | TransactionNoChainClause
+  | TransactionMode;
 
 export type AllTransactionStatements =
   | StartTransactionStmt
@@ -19,6 +20,44 @@ export interface StartTransactionStmt extends BaseNode {
   startKw: Keyword<"START" | "BEGIN">;
   behaviorKw?: Keyword<"DEFERRED" | "IMMEDIATE" | "EXCLUSIVE">;
   transactionKw?: Keyword<"TRANSACTION" | "WORK">;
+  modes?: ListExpr<TransactionMode>;
+}
+
+type TransactionMode =
+  | TransactionModeDeferrable
+  | TransactionModeNotDeferrable
+  | TransactionModeReadWrite
+  | TransactionModeReadOnly
+  | TransactionModeIsolationLevel;
+
+export interface TransactionModeDeferrable extends BaseNode {
+  type: "transaction_mode_deferrable";
+  deferrableKw: Keyword<"DEFERRABLE">;
+}
+
+export interface TransactionModeNotDeferrable extends BaseNode {
+  type: "transaction_mode_not_deferrable";
+  notDeferrableKw: [Keyword<"NOT">, Keyword<"DEFERRABLE">];
+}
+
+export interface TransactionModeReadWrite extends BaseNode {
+  type: "transaction_mode_read_write";
+  readWriteKw: [Keyword<"READ">, Keyword<"WRITE">];
+}
+
+export interface TransactionModeReadOnly extends BaseNode {
+  type: "transaction_mode_read_only";
+  readOnlyKw: [Keyword<"READ">, Keyword<"ONLY">];
+}
+
+export interface TransactionModeIsolationLevel extends BaseNode {
+  type: "transaction_mode_isolation_level";
+  isolationLevelKw: [Keyword<"ISOLATION">, Keyword<"LEVEL">];
+  levelKw:
+    | Keyword<"SERIALIZABLE">
+    | [Keyword<"REPEATABLE">, Keyword<"READ">]
+    | [Keyword<"READ">, Keyword<"COMMITTED">]
+    | [Keyword<"READ">, Keyword<"UNCOMMITTED">];
 }
 
 export interface CommitTransactionStmt extends BaseNode {
diff --git a/src/parser.pegjs b/src/parser.pegjs
index b7c3d71d..74886e9f 100644
--- a/src/parser.pegjs
+++ b/src/parser.pegjs
@@ -4688,11 +4688,12 @@ start_transaction_stmt
       transactionKw: read(tKw),
     });
   }
-  / &postgres kw:BEGIN tKw:(__ (TRANSACTION / WORK))? {
+  / &postgres kw:BEGIN tKw:(__ (TRANSACTION / WORK))? modes:(__ list$transaction_mode)? {
     return loc({
       type: "start_transaction_stmt",
       startKw: kw,
       transactionKw: read(tKw),
+      modes: read(modes),
     });
   }
   / &mysql kw:BEGIN tKw:(__ WORK)? {
@@ -4702,14 +4703,57 @@ start_transaction_stmt
       transactionKw: read(tKw),
     });
   }
-  / (&mysql / &postgres) kw:START tKw:(__ TRANSACTION) {
+  / (&mysql / &postgres) kw:START tKw:(__ TRANSACTION) modes:(__ list$transaction_mode)? {
     return loc({
       type: "start_transaction_stmt",
       startKw: kw,
       transactionKw: read(tKw),
+      modes: read(modes),
     });
   }
 
+transaction_mode
+  = transaction_mode_deferrable
+  / transaction_mode_not_deferrable
+  / transaction_mode_read_write
+  / transaction_mode_read_only
+  / transaction_mode_isolation_level
+
+transaction_mode_deferrable
+  = kw:(DEFERRABLE) {
+    return loc({ type: "transaction_mode_deferrable", deferrableKw: kw });
+  }
+
+transaction_mode_not_deferrable
+  = kw:(NOT __ DEFERRABLE) {
+    return loc({ type: "transaction_mode_not_deferrable", notDeferrableKw: read(kw) });
+  }
+
+transaction_mode_read_write
+  = kw:(READ __ WRITE) {
+    return loc({ type: "transaction_mode_read_write", readWriteKw: read(kw) });
+  }
+
+transaction_mode_read_only
+  = kw:(READ __ ONLY) {
+    return loc({ type: "transaction_mode_read_only", readOnlyKw: read(kw) });
+  }
+
+transaction_mode_isolation_level
+  = kw:(ISOLATION __ LEVEL __) levelKw:isolation_level_kw {
+    return loc({
+      type: "transaction_mode_isolation_level",
+      isolationLevelKw: read(kw),
+      levelKw: read(levelKw),
+    });
+  }
+
+isolation_level_kw
+  = SERIALIZABLE
+  / REPEATABLE __ READ
+  / READ __ COMMITTED
+  / READ __ UNCOMMITTED
+
 commit_transaction_stmt
   = kw:commit_kw tKw:(__ transaction_kw)? chain:(__ transaction_chain_clause)? {
     return loc({
@@ -7616,6 +7660,7 @@ list$string_literal = .
 list$table_func_call = .
 list$table_option_postgresql = .
 list$tablesample_arg = .
+list$transaction_mode = .
 list$transform_type = .
 list$trigger_transition = .
 list$type_param = .
@@ -8629,6 +8674,7 @@ COLUMNS             = kw:"COLUMNS"i             !ident_part { return loc(createK
 COMMENT             = kw:"COMMENT"i             !ident_part { return loc(createKeyword(kw)); }
 COMMENTS            = kw:"COMMENTS"i            !ident_part { return loc(createKeyword(kw)); }
 COMMIT              = kw:"COMMIT"i              !ident_part { return loc(createKeyword(kw)); }
+COMMITTED           = kw:"COMMITTED"i           !ident_part { return loc(createKeyword(kw)); }
 COMPACT             = kw:"COMPACT"i             !ident_part { return loc(createKeyword(kw)); }
 COMPRESSED          = kw:"COMPRESSED"i          !ident_part { return loc(createKeyword(kw)); }
 COMPRESSION         = kw:"COMPRESSION"i         !ident_part { return loc(createKeyword(kw)); }
@@ -8813,6 +8859,7 @@ INVOKER             = kw:"INVOKER"i             !ident_part { return loc(createK
 IS                  = kw:"IS"i                  !ident_part { return loc(createKeyword(kw)); }
 ISNULL              = kw:"ISNULL"               !ident_part { return loc(createKeyword(kw)); }
 ISODOW              = kw:"ISODOW"i              !ident_part { return loc(createKeyword(kw)); }
+ISOLATION           = kw:"ISOLATION"i           !ident_part { return loc(createKeyword(kw)); }
 ISOWEEK             = kw:"ISOWEEK"i             !ident_part { return loc(createKeyword(kw)); }
 ISOYEAR             = kw:"ISOYEAR"i             !ident_part { return loc(createKeyword(kw)); }
 ITERATE             = kw:"ITERATE"i             !ident_part { return loc(createKeyword(kw)); }
@@ -9028,6 +9075,7 @@ SECURITY            = kw:"SECURITY"i            !ident_part { return loc(createK
 SELECT              = kw:"SELECT"i              !ident_part { return loc(createKeyword(kw)); }
 SEQUENCE            = kw:"SEQUENCE"i            !ident_part { return loc(createKeyword(kw)); }
 SEQUENCES           = kw:"SEQUENCES"i           !ident_part { return loc(createKeyword(kw)); }
+SERIALIZABLE        = kw:"SERIALIZABLE"i        !ident_part { return loc(createKeyword(kw)); }
 SERVER              = kw:"SERVER"i              !ident_part { return loc(createKeyword(kw)); }
 SESSION             = kw:"SESSION"i             !ident_part { return loc(createKeyword(kw)); }
 SESSION_USER        = kw:"SESSION_USER"i        !ident_part { return loc(createKeyword(kw)); }
@@ -9107,6 +9155,7 @@ TUESDAY             = kw:"TUESDAY"i             !ident_part { return loc(createK
 TYPE                = kw:"TYPE"i                !ident_part { return loc(createKeyword(kw)); }
 UESCAPE             = kw:"UESCAPE"i             !ident_part { return loc(createKeyword(kw)); }
 UNBOUNDED           = kw:"UNBOUNDED"i           !ident_part { return loc(createKeyword(kw)); }
+UNCOMMITTED         = kw:"UNCOMMITTED"i         !ident_part { return loc(createKeyword(kw)); }
 UNDEFINED           = kw:"UNDEFINED"i           !ident_part { return loc(createKeyword(kw)); }
 UNION               = kw:"UNION"i               !ident_part { return loc(createKeyword(kw)); }
 UNIQUE              = kw:"UNIQUE"i              !ident_part { return loc(createKeyword(kw)); }
diff --git a/src/showNode/transaction.ts b/src/showNode/transaction.ts
index b54a815a..c0ba3470 100644
--- a/src/showNode/transaction.ts
+++ b/src/showNode/transaction.ts
@@ -4,7 +4,7 @@ import { FullTransformMap } from "../cstTransformer";
 
 export const transactionMap: FullTransformMap<string, AllTransactionNodes> = {
   start_transaction_stmt: (node) =>
-    show([node.startKw, node.behaviorKw, node.transactionKw]),
+    show([node.startKw, node.behaviorKw, node.transactionKw, node.modes]),
   commit_transaction_stmt: (node) =>
     show([node.commitKw, node.transactionKw, node.chain]),
   rollback_transaction_stmt: (node) =>
@@ -16,4 +16,10 @@ export const transactionMap: FullTransformMap<string, AllTransactionNodes> = {
     show([node.releaseKw, node.savepointKw, node.savepoint]),
   transaction_chain_clause: (node) => show([node.andChainKw]),
   transaction_no_chain_clause: (node) => show([node.andNoChainKw]),
+  transaction_mode_deferrable: (node) => show([node.deferrableKw]),
+  transaction_mode_not_deferrable: (node) => show([node.notDeferrableKw]),
+  transaction_mode_read_write: (node) => show([node.readWriteKw]),
+  transaction_mode_read_only: (node) => show([node.readOnlyKw]),
+  transaction_mode_isolation_level: (node) =>
+    show([node.isolationLevelKw, node.levelKw]),
 };
diff --git a/test/transactions.test.ts b/test/transactions.test.ts
index e990fb7c..6d40be79 100644
--- a/test/transactions.test.ts
+++ b/test/transactions.test.ts
@@ -32,6 +32,29 @@ describe("transactions", () => {
         testWc("BEGIN WORK");
       });
     });
+
+    dialect("postgresql", () => {
+      it("supports [NOT] DEFERRABLE", () => {
+        testWc("BEGIN NOT DEFERRABLE");
+        testWc("BEGIN DEFERRABLE");
+      });
+
+      it("supports READ {WRITE | ONLY}", () => {
+        testWc("BEGIN READ WRITE");
+        testWc("BEGIN READ ONLY");
+      });
+
+      it("supports ISOLATION LEVEL", () => {
+        testWc("BEGIN ISOLATION LEVEL SERIALIZABLE");
+        testWc("BEGIN ISOLATION LEVEL REPEATABLE READ");
+        testWc("BEGIN ISOLATION LEVEL READ COMMITTED");
+        testWc("BEGIN ISOLATION LEVEL READ UNCOMMITTED");
+      });
+
+      it("supports multiple transaction modes", () => {
+        testWc("BEGIN READ ONLY, ISOLATION LEVEL SERIALIZABLE, DEFERRABLE");
+      });
+    });
   });
 
   describe("committing transaction", () => {