Tuberous sclerosis is a multi-system-genetic disease occurring early in life with the classic triad of seizures, intellectual disability, and cutaneous angiofibroma. One of the most important psychiatric comorbidities in tuberous sclerosis is aggressive/disruptive behavior disorder. In this case report, treatment of a 14-years-old male with tuberous sclerosis, who was referred with severe behavioral problems secondary to mental retardation using clonidine is presented