Adam, E., R. H. Kaufman, J. L. Melnick, A. H. Levy and W. E. Rawls (Dept. of Virology and Epidemiology, Baylor College of Medicine, Houston, Texas 77025). Seroepidemiologic studies of herpesvirus type 2 and carcinoma of the cervix. III. Houston, Texas. Am J Epidemiol 96: 427–442, 1972.—Neutralizing antibody activity to herpesvirus type 1 and type 2 was quantified in sera from 85 women with cervical cancer and 367 control women. The mean titers of the antibody activity to herpesvirus type 2 were higher among women with cancer than among control women. Titers to type 2 virus increased with age up to the fourth decade of life among control women but no age dependency was observed among women with cancer. These observations suggest that a larger percentage of women with cervical cancer have higher type 2 antibody titers than control women but the antibodies were acquired earlier in life. To evaluate the relation between type 2 antibody activity and attributes associated with an increased risk of developing cervical cancer, a II/I index threshold was chosen at the level of the maximal case-control differences. The distribution of II/I values exceeding the threshold levels among cases and controls was examined according to age at first pregnancy, age at first marriage, number of live births, number of marriages and number of sex partners. The occurrence of II/I values exceeding the threshold value among control women with attributes associated with an increased risk of developing cancer was greater than among women without these attributes; however, significantly fewer of these women had positive values than women with cancer. In addition, significantly more cases had positive values than pair matched controls. These findings suggest that the association between herpesvirus type 2 and cervical cancer is not simply one of covariability of sexual promiscuousness.