The treatment of infertility in polycystic ovary syndrome (PCOS) associates lifestyle measures, and the use of drugs to induce ovulation. In this endeavour, clomifene citrate (CC) should be used as the first line of treatment, followed eventually by low dose gonadotrophin stimulation, as a second line. In rare cases, in case of failure of the CC treatment, ovarian drilling i.e. laparoscopic ovarian surgery (LOS), and finally assisted reproduction techniques can be used, if needed. Overall, ovulation induction (representing the CC-gonadotrophin paradigm) is highly effective with a cumulative singleton live birth rate of 72%. The use of insulin sensitizers i.e. metformin in PCOS should be restricted to women with glucose intolerance and/or insulin resistance. Based on recent data available, the routine use of this drug, alone, in ovulation induction is not recommended. (C) 2010 Published by Elsevier Masson SAS.