Objectives: To assess the prognostic value of coexisting coronary artery disease (CAD), Markis class, and ectasia ratio for major adverse cardiovascular events in patients with coronary artery ectasia (CAE). Methods: A total of 512 consecutive patients with angiographically proven CAE were enrolled. Coronary ectasia extent was graded using the Markis class, and ectasia severity was assessed based on the ectasia ratio. Patients were followed up for a median of 34.6 months. Results: In the current study, 76 cases had isolated CAE, while the remaining 436 cases had coexisting CAD (mixture CAE). Males (84.4%) were predominantly affected, and the right coronary artery (55.1%) was most commonly involved. During follow-up, 86 overall major adverse cardiovascular events were diagnosed. Kaplan-Meier analysis failed to reveal any differences between isolated and mixture CAE in both cumulative and event-free survival analyses (p = 0.429 and p = 0.277, respectively). Moreover, when patients were divided into 4 groups according to Markis class (type I-IV) or 2 groups based on the ectasia ratio (1.5-2.0 and >2.0), there was no significant difference in survival outcomes among the groups (p > 0.05). Conclusions: In this follow-up study with a relatively large sample, the survival rate of patients with CAE appeared to be independent of coexisting CAD and ectasia extent and severity.