The relationship between sexual activity and genitourinary excretion of cytomegalovirus (CMV) was evaluated in 1481 women at a sexually transmitted disease (STD) clinic. Among 951 who were CMV-seropositive, 16.6% had CMV isolated, from cervix alone in 9.4%, urine alone in 3.8%, and both sites in 4.2%. Isolation rates were highest in young women (P < .001). Compared with those with only cervical infection, women shedding from both cervix and urine were younger, began sexual activity when younger, had more recent partners, and a higher frequency of CMV-specific IgM, suggesting recent CMV infection. By logistic regression, cervical CMV excretion was associated with concomitant gonococcal infection (P = .008) and was less frequent in those using barrier contraception (P = .036). Isolated urinary excretion of CMV was not associated with sexual activity, concomitant cervical infections, or use of contraception. Cervical CMV infection is related to sexual activity, acquisition of other STDs, or exogenous reinfection, and urinary CMV is not.