Many retrospective studies have shown that hydrosalpinx is associated with poor in-vitro fertilization (IVF) outcome. The mechanism of the actual cause is not yet fully understood. A clinical practice of performing salpingectomy before IVF has developed, without any evidence from prospective trials. The aim of the present prospective randomized trial was to test if a salpingectomy prior to IVF was effective in terms of increased pregnancy rates. Patients with hydrosalpinx were randomized to either a laparoscopic salpingectomy or no intervention before IVF. A total of 204 patients was available for an intention-to-treat analysis and 192 actually started IVF. Clinical pregnancy rates per included patient were 36.6% in the salpingectomy group and 23.9% in the non-intervention group (not significant, P = 0.067) and the ensuing delivery rates were 28.6% and 16.3% (P = 0.045). The corresponding delivery rates per transfer cycle were 29.5% versus 17. 5% (not significant, P = 0.083). A subgroup analysis revealed significant differences in favour of salpingectomy, in implantation rates in patients with bilateral hydrosalpinges (25.6% versus 12.3%, P = 0.038) and in clinical pregnancy rates (45.7% versus 22.5%, P = 0.029) and delivery rates (40.0% versus 17.5%, P = 0.038) in patients with ultrasound visible hydrosalpinges. The delivery rate was increased 3.5-fold in patients with bilateral hydrosalpinges visible on ultrasound (P = 0.019).