Objectives:This study aimed to estimate the prognosis of dolichoectasia in non-cardioembolic transient ischemic attack (TIA) and minor stroke patients. Methods: Data were derived from the imaging subgroup of patients in the Clopidogrel in High-risk Patients with Acute Nondisabling Cerebrovascular Events (CHANCE) trial. Dolichoectasia was defined as ectasia (basilar artery diameter >45 mm) and dolichosis (either basilar artery bifurcation above the suprasellar cistern or lateral to the margin of the clivus or dorsum sellae). The prognosis included ischemic stroke recurrence and poor functional outcome (modified Rankin scale 2-6) at 12-month follow-up. The association of dolichoectasia with risk factors and prognosis of patients were assessed using multivariable Cox regression models. Results: Overall, 1089 patients with magnetic resonance images in the CHANCE trial were included in this subanalysis. A total of 98 (9.0%) patients were detected with dolichoectasia, and 106 (9.7%) patients had a recurrent ischemic stroke at 12 months. Small artery occlusion (SAO) was more prevalent in patients with dolichoectasia compared with those without dolichoectasia (29.6% vs. 22.7%, hazard ratio [HR] 2.87, 95% confidence interval [CI] 1.59-5.17, p < 0.001). However, multivariate analysis showed no association of dolichoectasia with 12-month recurrent stroke (9.2% vs. 9.8%, HR, 1.15; 95%CI, 0.32-4.12; p = 0.83) and poor functional outcome (7.6% vs. 8.4%, odds ratio, 1.22; 95%CI, 0.24-6.08;p = 0.81) in the current subgroup analysis. Conclusions: Dolichoectasia was significantly associated with SAO. There was no relationship between dolichoectasia and 12-month prognosis of patients with non-cardioembolic TIA or minor stroke.