Abstract : Anastomotic aneurysms (AAs) are a serious late complication of vascular reconstructive surgery, associated with significant morbidity and mortality. Identifying their predisposing risk factors is crucial for prevention and early detection. This study aimed to analyze the local and systemic risk factors contributing to the development of AAs following open vascular procedures. A prospective-retrospective cohort analytical study was conducted at the University Hospital of Latakia between January 2019 and January 2025. The study included 27 patients diagnosed with AAs following previous open vascular surgery. Data on demographics, comorbidities, surgical history, and aneurysm characteristics were collected and statistically analyzed. The mean patient age was 62.37 ± 7.28 years, with a significant male predominance (81.5%). The most common comorbidities were hypertension (77.8%) and cardiovascular disease (51.9%). The most frequent site for AA development was the aortofemoral anastomosis (70.4%). AAs occurred more frequently at prosthetic graft anastomoses (74%) than at native suture lines (26%). The leading suspected etiologies were degeneration of the host arterial wall (51.9%) and suture line failure (37%). The majority of AAs (88.9%) were detected incidentally during routine radiological surveillance. Degenerative host artery pathology and technical factors like suture failure are the primary culprits in AA formation, exacerbated by systemic factors like hypertension and smoking. Meticulous surgical technique, appropriate material selection, and lifelong clinical and radiological surveillance are paramount for prevention and timely elective repair.