Purpose Polycystic ovary syndrome (PCOS) is a gynecological endocrine disorder that is characterized by disturbances in ovarian blood flow and angiogenesis. The aim of this study was to determine the association of vascular endothelial growth factor (VEGF) and thrombospondin-1 (TSP-1) serum levels with the body mass index (BMI) in patients with PCOS compared with healthy subjects. Methods The study was conducted with 80 subjects in 3 PCOS groups, including normal weight, overweight, and obese PCOS groups, and a control group of healthy subjects (n=20). The participants in all groups completed a questionnaire comprising sociodemographic and obstetric questions. The PCOS diagnosis in the study subjects was confirmed based on the Rotterdam criteria, BMI was determined according to the World Health Organization guidelines, and the lipid accumulation product index was calculated for all groups. Venous blood samples were collected from all participants after fasting to measure the serum levels of fasting blood glucose (FBG), lipids, insulin, VEGF, TSP-1, and leptin. Results Our findings showed that the serum VEGF level was significantly higher in the normal BMI PCOS group than that in the control group (P=0.03), and the TSP-1 level was significantly lower in the obese PCOS group than that in the control group (P=0.04). Conclusions Our study demonstrated that alterations in VEGF and TSP-1 concentrations are dependent on BMI. Because abnormal ovarian angiogenesis is considered to be the main feature of PCOS, the study of ovarian angiogenic imbalance is proposed as a new tool for PCOS diagnosis and management. © by the authors. Licensee MDPL, Basel, Switzerland.