Human studies of the link between serum cholesterol and aggression have yielded equivocal results. Depending on the type of aggression studied (e.g., criminal violence or Type A hostility), investigators have found either a negative or a positive association between cholesterol and aggressive behavior. We conducted a retrospective analysis of aggressive incidents in a sample of hospitalized male forensic patients. The whole sample had lower cholesterol levels than the general population. Patients with low cholesterol levels (< 200 mg/dl) engaged in more frequent aggressive behavior but showed no difference in severity of aggression. They also showed no difference in verbal vs physical aggression. The relationship between cholesterol and frequency of aggression was curvilinear, with the most frequent acts of aggression committed by patients with moderately low cholesterol levels. Current research findings regarding the cholesterol-aggression association suggest the need for further clarification of the behavioral parameters under investigation.