Use of anabolic androgenic steroids among athletes has grown at an alarming rate in recent years, despite the knowledge that their use has resulted in such side effects as severe depression of high-density lipoprotein levels, increased low-density lipoprotein/cholesterol levels, and hepatocellular carcinoma. We report here the case of a 34-year-old man whose hobby was body building, in the course of which he had been taking various anabolic androgenic agents for four years. Seventeen days before a scheduled body physique contest, he developed an acute right hemiparesis and experienced difficulty in speaking. In the emergency room he developed a simple partial seizure activity; an electroencephalogram showed abnormal slowing suggestive of left hemispheric structural lesion. After rehabilitation, he was able to ambulate independently; he had mild motor weakness in the right upper extremity with no sensory changes at discharge. Physicians working with athletes who use anabolic androgenic steroids should warn them of the risk of stroke.