Nonsaccular vertebrobasilar aneurysms (NSVBAs) are linked to a high rate of aneurysm-related death. According to anecdotal evidence, brainstem infarction may be a sign of aneurysm rupture. The researchers wanted to see a link between brainstem infarction and NSVBA rupture. About Ninety-eight patients met the inclusion criteria for analysis with 591.3 person-years of follow-up. During the follow-up period, 20 patients had a perforator infarction. Ten patients (10.2%) had an aneurysm rupture during follow-up, and 26 patients (26.5%) died from aneurysm-related complications, with annual rupture and mortality rates of 1.7% and 4.4%, respectively. Five individuals who had a perforator infarction later had aneurysm rupture, with a median interval of 3 months (range 0–35 months) between the infarction and the rupture. Intraaneurysmal thrombus (RR 4.01, 95% CI 1.12–14.44, p = 0.033) and perforator infarction (RR 6.37, 95% CI 1.07–37.95, p = 0.042) were found to be independently related with aneurysm rupture on multivariate analysis. NSVBAs remain one of the most difficult clinical entities to treat, with a poor prognosis. These findings show that brainstem infarction caused by perforating artery occlusion could signify aneurysm rupture shortly.