The aim of this study was to determine prevalence of polycystic ovaries (PCO) and associated clinical and biochemical features among women with infertility attending gynaecological outpatient department (GOPD) at Muhimbili National Hospital (MNH) in Dar es Salaam, Tanzania. All women with infertility attending the GOPD from 11th September 2006 to 15th February 2007 were recruited to the study. Information on socio-demographic, obstetric and menstrual characteristics was collected. Anthropometric measurement, clinical examination of acne and hirsutism, vaginal ultrasonography for PCO and biochemical analysis of luteinizing hormone (LH), follicle stimulating hormone (FSH) and testosterone were performed. All 102 women who attended the GOPD during the study period due to infertility were recruited. Two women were excluded after diagnosis of pregnancy made by hormonal assay and ultrasonography thus remaining with 100 women for analysis. Oligomenorrhoea and acne were significantly higher in a group of women with PCO than among women with normal ovaries. The mean hirsutism score though was not significant, was higher in women with PCO than in women with normal ovaries (5.1±2.7 vs. 4±2.4, P