It has been suggested that tubal ligation may cause luteal phase defects. To assess this possibility, we performed a retrospective analysis of the incidence of luteal phase defects in 72 women who had undergone tubal sterilization. In preparation for tubal reanastomosis, late luteal phase endometrial biopsy was performed. The biopsy was dated in a blind manner and designated either normal or out of phase. This group of patients was compared with a group of 32 women seen for artificial insemination with donor sperm. Luteal phase defect was defined as two biopsies out of phase by two or more days. There were no cases of luteal phase defect in either of the two groups; luteal phase defects were found in 4% of all infertility patients seen during the time of this study. These data do not support the contention that sterilization by tubal ligation leads to an increased incidence of luteal phase defect.