BACKGROUNDHirsutism among women of fertile age is commonly seen in clinical practice, but the pattern of the disease in Saudi Arabs has not been studied. The aim of the study was to determine the clinical, biochemical and etiologic features of hirsutism in Saudi females.METHODS101 Saudi Arab women presenting with hirsutism at King Khalid University Hospital, Riyadh, Saudi Arabia, from 1 January 2000 to 31 December 2005 were prospectively assessed using the recently approved diagnostic guidelines for hyperandrogenic women with hirsutism.RESULTSPolycystic ovary syndrome (PCOS) was the cause of hirsutism in 83 patients (82%) followed by idiopathic hirsutism (IH) in 11 patients (11%). Others causes of hirsutism included late onset congenital adrenal hyperplasia in 4 patients (4%), microprolactinoma in 2 (2%) and Cushing’s syndrome in 1 (1%) patient. Age at presentation of PCOS was 24.5±6.6 years (mean±SD) and 51% of the subjects were obese. Furthermore, 74 (89%) of patients with PCOS had an oligo/anovulatory cycle while the remaining 9 patients (11%) maintained normal regular menstrual cycle. Luteinizing hormone and total testosterone were significantly higher in patients with PCOS than in those with IH (P<.05).CONCLUSIONSThe present data show PCOS to be the commonest cause of hirsutism in our clinical practice and PCOS is prominent amongst young obese females. However, further studies on a larger scale are needed to verify our findings.