OBJECTIVE: To compare the outcome of unstimulated in vitro maturation (IVM) and routine IVF/intracytoplasmic sperm injection (ICSI) for women with polycystic ovaries (PCO). DESIGN: Retrospective case–control study. SETTING: Fertility unit. PATIENT(S): Ninety-seven patients undergoing IVM were compared with 97 patients undergoing IVF. All had PCO and matched for age, infertility diagnosis, and ovulatory status. INTERVENTION(S): In vitro maturation cycles were unstimulated and hCG was administered 35–40 hours before oocyte retrieval. Oocytes were matured in vitro for 24–48 hours before insemination by ICSI. Endometrial priming with E₂ and P was commenced from the day of egg retrieval and one to two embryos were transferred on days 2–5 of development. Standard long protocol IVF/ICSI was used in the control group. MAIN OUTCOME MEASURE(S): Live birth rate per cycle and ovarian hyperstimulation syndrome (OHSS) rate. RESULT(S): Overall, 65% of IVM eggs matured in vitro in the IVM group. Implantation rates were significantly higher in the IVF group (19.4% vs. 12.9%) as clinical pregnancy rates (50.5% vs. 19.6%) and live birth rates (44.3% vs. 16.5%) than in the IVM group. The OHSS rate was significantly higher in the IVF group (8.2% vs. 0%). CONCLUSION(S): In vitro maturation is a safer and simpler alternative to conventional IVF for women with PCO. It avoids difficulties of gonadotropin stimulation and the risk of OHSS but has a significantly lower live birth rate. Current research projects aim to close the success gap between IVM and IVF.