BACKGROUND: The angioarchitecture and presentation of arteriovenous malformations (AVMs) associated with AVM hemorrhage may vary with patient age. Our aim was to determine the influence of patient age at diagnosis on hemorrhage patterns and outcomes. METHODS: A consecutive case series of 267 cases of ruptured AVMs was retrospectively analyzed. Hemorrhage patterns (intracerebral hemorrhage, subarachnoid hemorrhage, and intraventricular hemorrhage) were confirmed based on computed tomography imaging at initial diagnosis. Clinical outcomes were classified with a modified Rankin Score. These cases were analyzed with respect to age at diagnosis, hemorrhage patterns, Spetzler-Martin grades, and their clinical outcomes. RESULTS: During a mean 22.2 months follow-up time (range, 7 hours to 10 years), 212 cases (79.4%) were favorable (modified Rankin Score <= 2) and 55 cases (21.6%) were unfavorable (modified Rankin Score >= 3). The mean age was higher in patients with an unfavorable outcome at follow-up. In univariate analyses, different age groups were significantly associated with bleeding patterns (P = 0.022). Unfavorable outcome was associated with intracerebral hemorrhage (odds ratio, 0.330; 95% confidence interval, 0.142-0.768; P = 0.008) and evacuation of hematoma (odds ratio, 0.195; 95% confidence interval, 0.044-0.867; P = 0.025), whereas intraventricular hemorrhage, subarachnoid hemorrhage, and intraventricular drainage were significantly associated with a favorable outcome. Different age groups were not significantly associated with bleeding patterns, sex, and the location of the AVM, and Spetzler-Martin grades did not show a significant association with the severity of outcomes. CONCLUSIONS: Different age groups were significantly associated with bleeding patterns. Higher patient age, intracerebral hemorrhage, and evacuation of hematoma seem to be associated with an unfavorable outcome after AVM rupture.