Résumé : Background: The purpose of this study was to assess cumulative delivery rates in patients with non-obstructive or obstructive azoospermia following treatment by testicular sperm extraction (TESE)-ICSI. Methods: A cohort follow-up study was conducted. Between January 1994 and December 2000, 364 couples with obstructive azoospermia underwent a total of 609 fresh TESE-ICSI treatment cycles. In addition, 303 fresh TESE-ICSI treatment cycles were performed in 235 couples for non-obstructive azoospermia. This study included only patients in whom sperm was recovered. In the non-obstructive group, only patients with maturation arrest, atrophic sclerosis and germ cell aplasia were included. The main outcome measure was a delivery beyond 25 weeks gestation. Results: In patients with obstructive azoospermia, the crude delivery rate after three cycles was 35% while the expected cumulative delivery rate was 48% [95% confidence interval (CI), 41-55]. On the other hand, in patients with non-obstructive azoospermia, the crude cumulative delivery rate after three treatment cycles was 17% while the expected delivery rate was 31% (95% CI, 15-46). A high dropout rate in couples with both non-obstructive and obstructive azoospermia was observed (75 and 50% respectively, after the first cycle). Conclusion: This study shows that there is a value in performing several TESE-ICSI attempts in patients with obstructive and non-obstructive azoospermia. The estimates of the non-obstructive group beginning from the third cycle are less reliable due to fewer patients. However, overall, the obstructive group performed better than the non-obstructive group.