Several studies have supported that N-methyl-D-aspartate receptor antagonist can reduce the perception of postoperative pain. Hormonal fluctuations throughout the human menstrual cycle can influence pain pathways. In this pilot study, we evaluated postoperative pain in 22 female participants between the ages of 20 and 56 years undergoing laparoscopic abdominal procedures. Participants were randomly assigned to receive either placebo or ketamine at the induction of anesthesia. Progesterone levels were measured to determine menstrual phase. Visual analog scale scores were obtained at arrival into and discharge from the post anesthesia care unit. Total equipotent analgesic administration was also recorded. We found trends suggesting that women receiving ketamine and women in the luteal phase of their menstrual cycle had lower visual analog scale scores upon arrival to the unit. Ketamine recipients also received less rescue analgesic medication in the unit.