See: msdn.microsoft.com/en-us/library/9eee01cx(v=VS.100)Scott's answer will work for classes of checkboxes. Server Validate Event Args) _ Handles chk Age Validator. If you want individual checkboxes, you have to be a little sneakier. Net 3.5 Toolbar on the first examples and on the second one we are able to that manually ! It also works with the Validation Summary control... It's really helpful for me and helped me lot to complete my task. I had found another nice post over the internet which was also explained very well about Validating File Upload control for specific file type and required field, for more details of this post check out this link... There are few links that also helpful for developers.Validating File Upload control for specific file type and required field. This article have described to validate Check Box, Check Box List, Drop Down List, File Upload, Radio Button, Radio Button List, Text Box using jquery. If you set a validation control's , stating: "Control 'control ID' referenced by the Control To Validate property of 'validation Control ID' cannot be validated." There may be times, however, when you need to provide validation for a Check Box or Check Box List.