The presence of several infections was determined in tissue and serum samples from 34 cases and 23 controls seen in 1984-85 at Mulago Hospital in Kampala, Uganda. When assessing single infections, association with cervical cancer could be shown for 5 agents, namely by Southern blot assay for human papillomavirus types 16 and 18 (HPV), and by serological tests at varying levels of antibody titres, for herpes simplex virus type I and/or 2 (HSV), cytomegalovirus (CMV), Epstein-Barr virus, viral capsid antigen (EBV-VCA), and Chlamydia trachomatis (CLT). Due to interaction, HSV and CMV were associated with cervical cancer only when infection by both of these agents was demonstrable. In the assessment of the simultaneous presence of these 5 infections, moderately high antibody titres were taken as the cut-off point for infection by HSV, CMV, EBV-VCA, and CLT. This showed that 3 and 4 infections at a time were seen in the majority of the cases in contrast to the controls with essentially no more than 2 such infections. A linear trend in the rise of risk for cervical cancer was noted with increasing number of infections.