Abstract:Cortical venous thrombosis is a rare but treatable condition of the central nervous system which can manifest with bizarre signs and symptoms. However, a prompt clinical suspicion which can be confirmed by a T2 weighted MR image followed by venography is immediately needed to assess the patient and start therapy. We report a case of familial anti-thrombin III deficiency in a young male who presented to us with seizures. Successful treatment of this patient holds promise of an essentially non curable neurological condition.