AMINOCAPROIC acid is a useful agent in the management of hemophilia, particularly following extensive dental manipulations. The drug is widely used, in large measure because toxic reactions, including gastrointenstinal disturbances, dizziness, tinnitus, malaise, headache, rash, and conjunctival and nasal suffusion, are mild and rarely encountered. We report the case of a patient who experienced several of these side effects after aminocaproic acid infusion, then promptly progressed to a grand mal seizure, a toxic reaction not previously described. Report of a Case A 32-year-old man with mild hemophilia (factor VIII levels ranging from 10% to 15%) was admitted for dental scaling and prophylaxis. The patient's hemophilia had been identified two years prior to this admission, when he had bled excessively after dental extraction. At that time, von Willebrand's disease had been excluded by a normal bleeding time and ristocetin aggregation study. He had a long history of dental problems and had