Indonesia Background To investigate the correlation between menstrual cycle and follicular maturation process in patient with polycystic ovary (PCO) from the prevalence of menstrual cycle abnormalities. Objective To determine the correlation between menstrual cycle and follicular maturation process in patient with polycystic ovary at Asri Medical Center Yogyakarta, Indonesia. Methods This study was a retrospective analytical approach with case control study. The study population was female patients in the Department of Obstetrics and Gynecology Asri Medical Center Yogyakarta, Indonesia. While the sample in this study 178 female patients in 2014 at Department of Obstetrics and Gynecology Asri Medical Center that meet the inclusion and exclusion criteria and using total sampling technique. Retrieving data using instruments from medical records. Data were analyzed using chi-square analysis. Results Patients with oligomenorrhea 2.8 times more at risk of ovarian follicular maturation process disorder than patients who did not experi- ence oligomenorrhea with PCO (p = 0.003; OR = 2.8; 95 % CI = 1.409 to 5.633). Conclusion There is a correlation of the menstrual cycle length to the process of maturation of ovarian follicles in patients with PCO at Asri Medical Center. Women who experience menstrual cycle disorders such as oligomenorrhea have a higher risk impaired ovarian follicle maturation process.