Objective: There is evidence suggesting a strong genetic background of polycystic ovary syndrome (PCOS). We aim to study the metabolic and endocrine characteristics of PCOS women with and without a family history (FHx) of type 2 diabetes mellitus (T2DM) and PCOS. Design: Cross-sectional study. Methods: We analysed the association of T2DM FHx and PCOS FHx with metabolic and endocrine parameters in 714 PCOS women. Results: A positive FHx of T2DM and PCOS were prevalent in 36.8 and 21.4% of PCOS women respectively. We found an independent association of T2DM FHx with central fat accumulation, obesity, prediabetes, metabolic syndrome (MS), insulin resistance, low HDL and elevated blood pressure (P!0.05 for all). PCOS FHx was independently associated with prediabetes (P!0.05). We observed an independent association of PCOS FHx with clinical and biochemical hyperandrogenism (P!0.05 for all), whereas there was no independent association of T2DM FHx with hyperandrogenism. PCOS women with a positive FHx of both T2DM and PCOS had an adverse metabolic and endocrine profile including a linear increase in risk of obesity, central fat accumulation, MS, prediabetes and low HDL (P!0.05 for all). Conclusions: Our findings suggest that the assessment of FHx might allow risk stratification of PCOS women, which is important considering the high prevalence of PCOS.