With the recommendations of The American Fertility Society that all donors and recipients in a donor insemination programme should be screened for CMV antibody, we have documented the prevalence of CMV antibody in donors, recipients, and their partners in our clinic. Forty percent of our donors were CMV-positive, and in only 35% of the couples were both partners negative. The implications of using exclusively CMV-negative donors are examined. The necessity for further research on the detection and the transmission of various strains of CMV and the effects of cryopreservation on them is emphasized.