Polycystic ovarian syndrome (PCOS) is characterised by the clinical signs of oligo-amenorrhoea, infertility and hirsutism. Conventional treatment of PCOS includes a range of oral pharmacological agents, lifestyle changes and surgical modalities. Beta-endorphin presents in the follicular fluid of both normal and polycystic ovaries. It was demonstrated that the beta-endorphin levels in ovarian follicular fluid of otherwise healthy women who were undergoing ovulation were much higher than the levels measured in plasma.Given that acupuncture has an impact on beta-endorphin production, which may affect gonadotropin-releasing hormone (GnRH) secretion, it is postulated that acupuncture may have a role in ovulation induction and fertility. To assess the effectiveness and safety of acupuncture treatment of oligo/anovulatory women with polycystic ovarian syndrome (PCOS). We identified relevant studies from databases including the Cochrane Central Register of Controlled Trials (CENTRAL), Ovid MEDLINE, EMBASE, PsycINFO, CNKI and trial registries. The data are current to 19 October 2015. We included randomised controlled trials (RCTs) that studied the efficacy of acupuncture treatment for oligo/anovulatory women with PCOS. We excluded quasi- or pseudo-RCTs. Primary outcomes were live birth and ovulation (primary outcomes), and secondary outcomes were clinical pregnancy, restoration of menstruation, multiple pregnancy, miscarriage and adverse events. We assessed the quality of the evidence using GRADE methods. Two review authors independently selected the studies, extracted data and assessed risk of bias. We calculated Mantel-Haenszel odds ratios (ORs) and mean difference (MD) and 95% confidence intervals (CIs). We included five RCTs with 413 women. They compared true acupuncture versus sham acupuncture (two RCTs), true acupuncture versus relaxation (one RCT), true acupuncture versus clomiphene (one RCT) and electroacupuncture versus physical exercise (one RCT). Four of the studies were at high risk of bias in at least one domain.No study reported live birth rate. Two studies reported clinical pregnancy and found no evidence of a difference between true acupuncture and sham acupuncture (OR 2.72, 95% CI 0.69 to 10.77, two RCTs, 191 women, very low quality evidence).Three studies reported ovulation. One RCT reported number of women who had three ovulations during three months of treatment but not ovulation rate. One RCT found no evidence of a difference in mean ovulation rate between true and sham acupuncture (MD -0.03, 95% CI -0.14 to 0.08, one RCT, 84 women, very low quality evidence). However, one other RCT reported very low quality evidence to suggest that true acupuncture might be associated with higher ovulation frequency than relaxation (MD 0.35, 95% CI 0.14 to 0.56, one RCT, 28 women).Two studies reported menstrual frequency. One RCT reported true acupuncture reduced days between menstruation more than sham acupuncture (MD 220.35, 95% CI 252.85 to 187.85, 146 women). One RCT reported electroacupuncture increased menstrual frequency more than no intervention (0.37, 95% CI 0.21 to 0.53, 31 women).There was no evidence of a difference between the groups in adverse events. Evidence was very low quality with very wide CIs and very low event rates.Overall evidence was low or very low quality. The main limitations were failure to report important clinical outcomes and very serious imprecision. Thus far, only a limited number of RCTs have been reported. At present, there is insufficient evidence to support the use of acupuncture for treatment of ovulation disorders in women with PCOS.