For some couples, comprehensive evaluation of both partners does not identify an etiology for their infertility. Specifically, test results identify a normal semen analysis, evidence of ovulation, a normal uterine cavity, and patent fallopian tubes. Approximately 15%of couples are considered to have unexplained infertility. This diagnosis usually signifies the presence of one or more mild abnormalities in the highly orchestrated sequence of events that results in successful conception. These abnor-malities may lie below the level of detection of current tests or may not be detected by current tests. These couples have a low rate of spontaneous conception, approximately 1% to 3% each month; this rate is influenced by the age of the female partner and the duration of infertility. If laparoscopy is performed on the female partner, subtle abnormalities such as pelvic adhesions and mild endometriosis may be identified and treated. However, it is reasonable to proceed with medical treatment of infertility without performing laparoscopy.