Objective The aim was to determine the number and the grade of oocyte-corona-cumulus complex (OCCC) and the most viable embryos for transfer in women with endometriosis compared to those with tubal factor infertility. Study methods Patients underwent in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) at the Yale IVF program. The endometriosis group of 135 patients was monitored in 262 consecutive cycles. The controls consisted of 103 patients with tubal factor infertility undergoing 203 consecutive assisted reproductive technology (ART) cycles. All the patients underwent laparoscopy before IVF treatment. Response to gonadotropins, the oocyte and embryo grade, fertilization, cleavage, implantation, pregnancy, delivery and abortion rates were noted. Results Oocyte-corona-cumulus complex (OCCC), two-pronuclear (2PN) oocytes, and the grade 1 and 2 embryos on days 2 and 3 were lower in women with endometriosis compared to those with tubal factor infertility. Higher total gonadotropin requirements, fewer mature follicles, lower peak E2, a lower number of oocytes collected, and higher cancellation rates were found with the endometriosis group compared to controls. However, no differences were found in fertilization, cleavage, implantation, pregnancy, miscarriage, and delivery rates between the endometriosis and tubal factor groups. Conclusions Despite the lesser quality of oocytes and embryo grading and diminished ovarian reserve, the presence of endometriosis does not affect implantation and delivery rates in patients undergoing ART procedures.