Cervicovaginal cells were obtained from 114 women undergoing intrauterine insemination and 21 women undergoing donor insemination. Monoclonal antibodies were used to identify leukocyte subpopulations in women with nonepithelial cell counts greater than 2 X 10(5) (termed asymptomatic cervicovaginal leukocytosis). Leukocyte counts exceeding this number were not found in any of the women undergoing donor insemination; however, greater than 2 X 10(5) leukocytes were detected in 22% of the infertile women. Granulocytes predominated; lymphocytes and macrophages were detected in only 8 of 114 samples. Women with cervical factor infertility had a significantly higher incidence of asymptomatic cervicovaginal leukocytosis than women with either male factor or unexplained infertility. These data suggest that cervicovaginal leukocytes may play a role in cervical factor infertility since soluble products of activated leukocytes are known to adversely affect reproduction.