Aneurysmal subarachnoid hemorrhage (aSAH) is a life-threatening and life-limiting disease with high mortality and disability rates. Herein, we aim to explore the preventive effect of aminocaproic acid combined with nimodipine on short-term rebleeding in patients with aSAH. Retrospectively, the medical data of patients with aSAH (n = 256) were collected. According to different treatment methods, patients were categorized into the aminocaproic acid + nimodipine group (n = 152) and the nimodipine group (n = 104), and were treated for 1 week. Baseline characteristics, incidence of rebleeding, average velocity of cerebral artery blood flow, cerebral vasospasm index, vascular endothelial function, complications, and adverse events were analyzed between the two groups. After 1-week treatment, compared to the nimodipine group, the aminocaproic acid + nimodipine group exhibited lower incidence of rebleeding, notable decreases in average velocity of cerebral artery blood flow and the cerebral vasospasm index, and downregulation of endothelin-1 and vascular endothelial growth factor (P < 0.05). There were no significant differences about complications and adverse events between the two groups. Aminocaproic acid combined with nimodipine is superior to nimodipine alone in preventing the short-term rebleeding in patients with aSAH, and has good safety.