Background and purpose Subarachnoid hemorrhage (SAH) caused by intracranial aneurysm (IA) rupture is a life-threatening condition with high mortality and morbidity. Autoimmune diseases (ADs) induce systemic inflammation that may accelerate vascular remodeling, predisposing IAs to rupture. This study aimed to investigate the risk factors for rupture in IAs associated with ADs. Methods This multicenter retrospective study included patients aged >= 18 years from three institutions between January 2017 and January 2022. Morphological parameters such as aspect ratio (AR), size ratio (SR), aneurysm shape, and daughter sac presence were measured. Statistical analyses included multivariate logistic regression to assess rupture risk factors. Results A total of 254 patients with 311 IAs were analyzed, of which 105 were ruptured. Multivariate logistic regression identified AR (adjusted OR = 2.267, 95% CI: 1.442-3.563), current smoking (adjusted OR = 11.69, 95% CI: 1.580-86.401), previous smoking (adjusted OR = 15.98, 95% CI: 1.943-131.367), current drinking (adjusted OR = 9.32, 95% CI: 1.273-68.300), and the presence of daughter sacs (adjusted OR = 2.073, 95% CI: 1.001-4.291) as significant independent risk factors for rupture. Conclusion This study highlights those specific morphological features, including AR, irregular shape, daughter sac presence, and aneurysm location, significantly contribute to rupture risk in IAs associated with ADs. Lifestyle factors such as smoking and drinking further exacerbate this risk. These findings may provide valuable insights for clinical management and preventive strategies in this high-risk patient population.