Objective: To test the hypothesis that IVF-ET pregnancy rates (PRs) for patients with tubal factor infertility are decreased in patients with hydrosalpinges and that surgical correction reverses this effect. Design: Retrospective chart review. Setting: Private practice IVF-ET program. Patient(s): Patients (n = 160) undergoing 238 cycles of IVF-ET were stratified into groups based on the presence of hydrosalpinges and whether surgical correction had been performed. Patients >39 years old and patients with male factor infertility were excluded from the study, Intervention(s): Patients with hydrosalpinges were offered surgical correction, Main Outcome Measure(s): Clinical pregnancy defined by an intrauterine gestational sac, Result(s): Patients with hydrosalpinges had significantly decreased implantation rates and PRs per transfer (2.8% and 8.5%, respectively) than patients with tubal factor infertility but without hydrosalpinges (15.7% and 38.6%), Surgical correction improved implantation rates and PRs in patients with prior failed cycles (16.1% and 37.5%) and in patients undergoing surgery before IVF-ET (21.8% and 51.7%), The type of surgery performed did not affect success rates in the small number of patients evaluated. Conclusion(s): The presence of a hydrosalpinx during an IVF-ET cycle results in significant decreases in implantation rates and PRs. Surgical treatment of hydrosalpinges before IVF-ET cycles improves implantation rates and PRs. (C) 1998 by American Society for Reproductive Medicine.