Background: Left ventricular (LV) aneurysm is a severe complication with significant clinical implications. Differences between ischemic and non-ischemic LV aneurysms remain unclear. This study aimed to analyze their distinct clinical profiles, locations, and associations with ventricular tachycardia (VT). Methods: In this retrospective cross-sectional study, we analyzed inpatients with LV aneurysm at the First Affiliated Hospital of Nanjing Medical University from January 1, 2018, to October 5, 2023. Data included demographics, medical history, laboratory results, echocardiographic findings, and electrocardiographic findings. Multivariable logistic regressions assessed the association between aneurysm etiology and pre-admission VT. Results: We included 436 patients, comprising 401 with ischemic LV aneurysms and 35 with non-ischemic LV aneurysms. Non-ischemic LV aneurysms were associated with younger age and lower prevalence of hypertension, diabetes, and smoking (all P < 0.05). Patients with non-ischemic LV aneurysms had a higher Simpson’s LV ejection fraction (46.2 ± 14.5% vs. 40.8 ± 8.9%, P = 0.037). Apex involvement was less prevalent in non-ischemic LV aneurysms (68.6% vs. 91.3%; P < 0.001), which were more commonly located in basal segments like the basal inferolateral region (22.9% vs. 1.3%; P < 0.001). Pre-admission VT was more prevalent in non-ischemic LV aneurysms (42.9% vs. 13.3%; P < 0.001). Non-ischemic LV aneurysm was independently associated with increased odds of pre-admission VT (fully-adjusted OR: 8.49, 95% CI: 2.60–27.74; P < 0.001). Conclusions: Non-ischemic LV aneurysms had distinct baseline characteristics compared to ischemic LV aneurysms. Non-ischemic LV aneurysm was also associated with a higher prevalence of pre-admission VT. Further studies should explore underlying mechanisms and targeted strategies.