Sera from 133 cervical cancer patients and 154 healthy women (controls) from Spain and Colombia were tested in IgG-specific ELISAs for the presence of antibodies against seven peptides derived from five open-reading frames of human papillomavirus (HPV) type 16. Three of the peptides corresponded to overlapping regions of the N-terminal half of E7 protein; the other peptides corresponded to selected regions of E2, E4, L1, and L2 proteins. The prevalence of antibodies against E2 and E7 peptides was significantly different between patients and controls. The most marked differences were for E7 peptides. HPV DNA polymerase chain reaction diagnoses of cervical scrapes were available; these were correlated with serologic findings. In HPV-16 DNA-positive patients, E7 antibodies were more broadly and more strongly reactive than in other patient groups.