A randomized, controlled study was conducted in 51 patients to investigate the effect of aspirin administration on traumatic hyphema. Aspirin tablets 500 mg tid were administered for seven days. Rebleeding was found in three of 23 eyes of patients who had received aspirin and in two of 28 eyes of control patients. This difference was not statistically significant (P = .405), proving that aspirin is not an important factor in rebleeding in patients with hyphema.