Abstract Disclosure: M.O. Premaor: None. G. Risseti: None. J. Piovezan: None. F.V. Comim: None. Polycystic ovary syndrome (PCOS) is a complex and multifaceted disorder that may affect bone health. Controversial results have emerged regarding whether PCOS is protective or increases the risk of bone frailty. We conducted a systematic review and meta-analysis of published research on bone mineral density (BMD), bone markers, and the risk of fractures in individuals with PCOS. We searched MEDLINE, Embase, and conference s and preprints. Studies were eligible if the PCOS was defined according to the NIH criteria, the Rotterdam ESHRE/ASRM-Sponsored PCOS Consensus Workshop Group criteria, AE-PCOS society criteria, or ICD codes. The endpoints studied included fractures, bone mineral density (BMD), and bone markers. The study protocol is available at PROSPERO (CRD42016049664). From the 3322 studies identified in the databases, 111 had their full texts evaluated, and 31 studies met the inclusion criteria for qualitative analysis. Overall, cross-sectional studies included 1822 individuals with PCOS and 1374 controls, while cohort studies incorporated 30305 women with PCOS and 101907 controls. No differences were observed between individuals with PCOS and the control group in the pooled analysis for the whole group. Nevertheless, contrasting profiles emerged after stratification using a BMI cutoff of 27 kg/m2. Women with PCOS and a mean BMI <27 kg/m2 exhibited lower spine BMD (MD -0.060; 95% CI, -0.110 and -0.011) and total hip BMD (MD -0.042; 95% CI, -0.068 and -0.017), and increased bone resorption marker (CTX) levels (SMD 0.38; 95%CI 0.03 and 0.72). Conversely, women with PCOS and a mean >27 kg/m2 exhibited increased spine BMD (MD 0.029; CI 95%, 0.009 to 0.048) and total hip BMD (MD 0.036; CI 95%, 0.010 to 0.063), with no significant changes in bone resorption markers. Due to the limited number of longitudinal studies available, it was not possible to determine the risk of bone fractures in both groups. In conclusion, the findings of this systematic review show a negative impact of PCOS on bone health in women with a BMI <27 kg/m2, suggesting that increased surveillance and research for bone disease may be necessary for this particular group. Presentation: 6/3/2024