BACKGROUND Polycystic ovary syndrome (PCOS) is a common endocrine condition affecting women of reproductive age and characterized by chronic anovulation, hyperandrogenism, and polycystic ovaries. There are no published data on this syndrome in Libyan patients. OBJECTIVE To assess the frequency of clinical and biochemical features of PCOS in our patient population, and to compare this with data collected in other parts of the world. METHODS A retrospective analysis of patient records at the endocrine clinic in Benghazi was undertaken. Patient inclusion was according to Rotterdam ESHRE/ASRM criteria. Clinical features, associated diseases, family history, hormone levels, and ultrasonography results were analyzed. RESULTS The mean age of the 318 PCOS patients at presentation was 25.8 years (range 15-44 years), and the majority (67%) were 20-29 years old at presentation. Of all patients, 57% were obese (BMI≥30), 93% had oligo-/amenorrhea, 91% were hirsute, and 74% had ultrasound features of polycystic ovaries. Diabetes mellitus was diagnosed in 9% of all PCOS patients and hypertension in 4%. Total serum testosterone was elevated in 26% of the patients, and serum prolactin was elevated in 31%. Thyroid disease was noted among 5.3% of the patients, and a history of diabetes or hypertension among first-degree relatives was seen in (16%) and (8%) of the patients respectively. CONCLUSIONS Chronic anovulation and hirsutism are the dominant features of PCOS in our patient population. More than half were obese, and the prevalence of diabetes, hypertension and thyroid disease in our patients seemed to be underestimated in comparison to other parts of the world.