diff --git a/src/Api/Controllers/Payload/Requests/Users/UpdateUserRequest.cs b/src/Api/Controllers/Payload/Requests/Users/UpdateUserRequest.cs
index d162c28a..c30e9871 100644
--- a/src/Api/Controllers/Payload/Requests/Users/UpdateUserRequest.cs
+++ b/src/Api/Controllers/Payload/Requests/Users/UpdateUserRequest.cs
@@ -14,10 +14,6 @@ public class UpdateUserRequest
     /// </summary>
     public string? LastName { get; set; }
     /// <summary>
-    /// New role of the user to be updated
-    /// </summary>
-    public string Role { get; set; } = null!;
-    /// <summary>
     /// New position of the user to be updated
     /// </summary>
     public string? Position { get; set; }
diff --git a/src/Api/Controllers/UsersController.cs b/src/Api/Controllers/UsersController.cs
index dc2b406e..cc0c4ccc 100644
--- a/src/Api/Controllers/UsersController.cs
+++ b/src/Api/Controllers/UsersController.cs
@@ -141,7 +141,6 @@ public async Task<ActionResult<Result<UserDto>>> Update([FromRoute] Guid userId,
             UserId = userId,
             FirstName = request.FirstName,
             LastName = request.LastName,
-            Role = request.Role,
             Position = request.Position,
         };
         var result = await Mediator.Send(command);
diff --git a/src/Application/Users/Commands/UpdateUser.cs b/src/Application/Users/Commands/UpdateUser.cs
index 4d894cc0..00b27531 100644
--- a/src/Application/Users/Commands/UpdateUser.cs
+++ b/src/Application/Users/Commands/UpdateUser.cs
@@ -1,16 +1,66 @@
+using Application.Common.Interfaces;
 using Application.Users.Queries;
+using AutoMapper;
+using FluentValidation;
 using MediatR;
+using Microsoft.EntityFrameworkCore;
 
 namespace Application.Users.Commands;
 
 public class UpdateUser
 {
+    public class Validator : AbstractValidator<Command>
+    {
+        public Validator()
+        {
+            RuleLevelCascadeMode = CascadeMode.Stop;
+
+            RuleFor(x => x.FirstName)
+                .MaximumLength(50).WithMessage("FirstName can not exceed 50 characters.");
+
+            RuleFor(x => x.LastName)
+                .MaximumLength(50).WithMessage("LastName can not exceed 50 characters.");
+
+            RuleFor(x => x.Position)
+                .MaximumLength(64).WithMessage("Position can not exceed 64 characters.");
+        }
+    }
     public record Command : IRequest<UserDto>
     {
         public Guid UserId { get; init; }
         public string? FirstName { get; init; }
         public string? LastName { get; init; }
-        public string Role { get; init; } = null!;
         public string? Position { get; init; }
     }
+    
+    public class CommandHandler : IRequestHandler<Command, UserDto>
+    {
+        private readonly IApplicationDbContext _context;
+        private readonly IMapper _mapper;
+
+        public CommandHandler(IApplicationDbContext context, IMapper mapper)
+        {
+            _context = context;
+            _mapper = mapper;
+        }
+
+        public async Task<UserDto> Handle(Command request, CancellationToken cancellationToken)
+        {
+            var user = await _context.Users
+                .FirstOrDefaultAsync(x => x.Id.Equals(request.UserId), cancellationToken: cancellationToken);
+
+            if (user is null)
+            {
+                throw new KeyNotFoundException("User does not exist.");
+            }
+
+            user.FirstName = request.FirstName;
+            user.LastName = request.LastName;
+            user.Position = request.Position;
+
+            var result = _context.Users.Update(user);
+            await _context.SaveChangesAsync(cancellationToken);
+            return _mapper.Map<UserDto>(result.Entity);
+        }
+    }
 }
\ No newline at end of file
diff --git a/tests/Application.Tests.Integration/Users/Commands/UpdateUserTests.cs b/tests/Application.Tests.Integration/Users/Commands/UpdateUserTests.cs
new file mode 100644
index 00000000..3214a6bd
--- /dev/null
+++ b/tests/Application.Tests.Integration/Users/Commands/UpdateUserTests.cs
@@ -0,0 +1,60 @@
+using Application.Identity;
+using Application.Users.Commands;
+using FluentAssertions;
+using Xunit;
+
+namespace Application.Tests.Integration.Users.Commands;
+
+public class UpdateUserTests : BaseClassFixture
+{
+    public UpdateUserTests(CustomApiFactory apiFactory) : base(apiFactory)
+    {
+    }
+
+    [Fact]
+    public async Task ShouldUpdateUser_WhenUpdateDetailsAreValid()
+    {
+        // Arrange
+        var user = CreateUser(IdentityData.Roles.Employee, "randompassword");
+        await AddAsync(user);
+
+        var command = new UpdateUser.Command()
+        {
+            UserId = user.Id,
+            FirstName = "khoa",
+            LastName = "ngu",
+            Position = "IDK",
+        };
+        
+        // Act
+        var result = await SendAsync(command);
+        
+        // Assert
+        result.FirstName.Should().Be(command.FirstName);
+        result.LastName.Should().Be(command.LastName);
+        result.Position.Should().Be(command.Position);
+        
+        // Cleanup
+        Remove(user);
+    }
+    
+    [Fact]
+    public async Task ShouldThrowKeyNotFoundException_WhenThatUserDoesNotExist()
+    {
+        // Arrange
+        var command = new UpdateUser.Command()
+        {
+            UserId = Guid.NewGuid(),
+            FirstName = "khoa",
+            LastName = "ngu",
+            Position = "IDK",
+        };
+        
+        // Act
+        var action = async () => await SendAsync(command);
+        
+        // Assert
+        await action.Should().ThrowAsync<KeyNotFoundException>()
+            .WithMessage("User does not exist.");
+    }
+}
\ No newline at end of file