Paired sera from 21 women whose children had malignancy and 15 women who were diagnosed as having abnormal pathology in the cervix and matched normal controls were studied for presence of BK antibodies by the ELISA technique. BK antibody was detected in 74% of the women in the first serum sample obtained. Evidence of BK antibody rises were observed in eight of 72 women (11%) and was distributed equally among women with abnormal children and women with abnormal pathology in the cervix and controls and that the level of antibody was not influenced by vaccination with killed polio vaccine during this pregnancy. Our serological data fails to show an association between infection with BK virus and malignancy in the children or carcinoma in situ of the cervix.