This study goaled to evaluate the ABO/Rh blood group distribution and its relationship with clinical and biochemical factors in polycystic ovary syndrome (PCOS) patients. ABO/Rh blood group distribution of the patients and the healthy individuals were compared. In addition, the features of clinical and biochemical factors were compared according to the ABO/Rh blood groups. Two hundred and sixty-five patients were involved in the study. At the time of diagnosis, hirsutism (86%) and oligomenorrhea (80.9%) were the most prevalent symptoms. There were 166 (62.6%) patients with baseline ultrasonography results consistent with PCOS. In 111 (41.9%) patients, insulin resistance was found. ABO blood group distributions in the patient (42.6% A, 17% B, 9.4% AB, 30.9% O) and control (42% A, 16% B, 8% AB, 34% O) groups were found to be similar (P = .9). There was no difference between oligomenorrhea, hirsutism, hair loss, acne, obesity, high androgen level, insulin resistance, and ultrasound characteristics according to ABO/Rh blood groups. In this study, ABO/Rh blood group distribution in individuals with PCOS was found to be similar to healthy individuals, and it was determined that ABO/Rh blood group was not a risk factor for PCOS. In addition, no correlation was found between the clinical and biochemical characteristics of the patients at the time of diagnosis and the ABO/Rh blood group.