diff --git a/model/states.go b/model/states.go
index b7b11ab..3b69238 100644
--- a/model/states.go
+++ b/model/states.go
@@ -18,8 +18,29 @@ import (
 	"encoding/json"
 	"fmt"
 	"strings"
+
+	validator "github.com/go-playground/validator/v10"
+	val "github.com/serverlessworkflow/sdk-go/v2/validator"
 )
 
+func init() {
+	val.GetValidator().RegisterStructValidation(stateStructLevelValidation, State{})
+}
+
+func stateStructLevelValidation(structLevel validator.StructLevel) {
+	state := structLevel.Current().Interface().(State)
+
+	hasTransition := state.Transition != nil
+	isEnd := state.End != nil && state.End.Terminate
+
+	// TODO: Improve message errors
+	if !hasTransition && !isEnd {
+		structLevel.ReportError(nil, "State.Transition,State.End", "transition,end", "required", "")
+	} else if hasTransition && isEnd {
+		structLevel.ReportError(nil, "State.Transition", "transition", "required_without", "end")
+	}
+}
+
 // StateType ...
 type StateType string
 
@@ -53,7 +74,7 @@ type BaseState struct {
 	// State type
 	Type StateType `json:"type" validate:"required"`
 	// States error handling and retries definitions
-	OnErrors []OnError `json:"onErrors,omitempty"  validate:"omitempty,dive"`
+	OnErrors []OnError `json:"onErrors,omitempty" validate:"omitempty,dive"`
 	// Next transition of the workflow after the time delay
 	Transition *Transition `json:"transition,omitempty"`
 	// State data filter
diff --git a/model/states_test.go b/model/states_test.go
new file mode 100644
index 0000000..498ec8e
--- /dev/null
+++ b/model/states_test.go
@@ -0,0 +1,108 @@
+// Copyright 2022 The Serverless Workflow Specification Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//	http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package model
+
+import (
+	"testing"
+
+	val "github.com/serverlessworkflow/sdk-go/v2/validator"
+	"github.com/stretchr/testify/assert"
+)
+
+var stateTransitionDefault = State{
+	BaseState: BaseState{
+		Name: "name state",
+		Type: StateTypeOperation,
+		Transition: &Transition{
+			NextState: "next name state",
+		},
+	},
+	OperationState: &OperationState{
+		ActionMode: "sequential",
+		Actions: []Action{
+			{},
+		},
+	},
+}
+
+var stateEndDefault = State{
+	BaseState: BaseState{
+		Name: "name state",
+		Type: StateTypeOperation,
+		End: &End{
+			Terminate: true,
+		},
+	},
+	OperationState: &OperationState{
+		ActionMode: "sequential",
+		Actions: []Action{
+			{},
+		},
+	},
+}
+
+func TestStateStructLevelValidation(t *testing.T) {
+	type testCase struct {
+		name     string
+		instance State
+		err      string
+	}
+
+	testCases := []testCase{
+		{
+			name:     "state transition success",
+			instance: stateTransitionDefault,
+			err:      ``,
+		},
+		{
+			name:     "state end success",
+			instance: stateEndDefault,
+			err:      ``,
+		},
+		{
+			name: "state end and transition",
+			instance: func() State {
+				s := stateTransitionDefault
+				s.End = stateEndDefault.End
+				return s
+			}(),
+			err: `Key: 'State.State.Transition' Error:Field validation for 'State.Transition' failed on the 'required_without' tag`,
+		},
+		{
+			name: "state without end and transition",
+			instance: func() State {
+				s := stateTransitionDefault
+				s.Transition = nil
+				return s
+			}(),
+			err: `Key: 'State.State.Transition,State.End' Error:Field validation for 'State.Transition,State.End' failed on the 'required' tag`,
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			err := val.GetValidator().Struct(tc.instance)
+
+			if tc.err != "" {
+				assert.Error(t, err)
+				if err != nil {
+					assert.Equal(t, tc.err, err.Error())
+				}
+				return
+			}
+			assert.NoError(t, err)
+		})
+	}
+}
diff --git a/model/workflow.go b/model/workflow.go
index b76b48a..2fcd630 100644
--- a/model/workflow.go
+++ b/model/workflow.go
@@ -86,17 +86,17 @@ func workflowStructLevelValidation(structLevel validator.StructLevel) {
 		}
 	}
 
-	// start state name exists in states list
+	// start state name exist in workflow states list
 	if wf.BaseWorkflow.Start.StateName != "" {
-		startExists := false
+		startExist := false
 		for _, state := range wf.States {
 			if state.Name == wf.BaseWorkflow.Start.StateName {
-				startExists = true
+				startExist = true
 				break
 			}
 		}
-		if !startExists {
-			structLevel.ReportError(reflect.ValueOf(wf.BaseWorkflow.Start.StateName), "Start", "start", "startnotexists", "")
+		if !startExist {
+			structLevel.ReportError(reflect.ValueOf(wf.BaseWorkflow.Start.StateName), "Start", "start", "startnotexist", "")
 		}
 	}
 }
diff --git a/model/workflow_test.go b/model/workflow_test.go
index c02024a..90b6813 100644
--- a/model/workflow_test.go
+++ b/model/workflow_test.go
@@ -36,21 +36,41 @@ var workflowStructDefault = Workflow{
 			StateName: "name state",
 		},
 	},
-	States: []State{{
-		BaseState: BaseState{
-			Name: "name state",
-			Type: StateTypeOperation,
+	States: []State{
+		{
+			BaseState: BaseState{
+				Name: "name state",
+				Type: StateTypeOperation,
+				Transition: &Transition{
+					NextState: "next name state",
+				},
+			},
+			OperationState: &OperationState{
+				ActionMode: "sequential",
+				Actions: []Action{
+					{},
+				},
+			},
 		},
-		OperationState: &OperationState{
-			ActionMode: "sequential",
-			Actions: []Action{
-				{},
+		{
+			BaseState: BaseState{
+				Name: "next name state",
+				Type: StateTypeOperation,
+				End: &End{
+					Terminate: true,
+				},
+			},
+			OperationState: &OperationState{
+				ActionMode: "sequential",
+				Actions: []Action{
+					{},
+				},
 			},
 		},
-	}},
+	},
 }
 
-func TestValidationAsStructLevelValidation(t *testing.T) {
+func TestWorkflowStructLevelValidation(t *testing.T) {
 	type testCase[T any] struct {
 		name     string
 		instance T
@@ -120,7 +140,7 @@ Key: 'Workflow.BaseWorkflow.Key' Error:Field validation for 'Key' failed on the
 				}
 				return w
 			}(),
-			err: `Key: 'Workflow.Start' Error:Field validation for 'Start' failed on the 'startnotexists' tag`,
+			err: `Key: 'Workflow.Start' Error:Field validation for 'Start' failed on the 'startnotexist' tag`,
 		},
 		{
 			name: "valid ContinueAs",