Recent evidence on the importance of sexual history and sexually transmissible agents in cervical cancer has been reported. Case-control studies have frequently demonstrated increased risk of cervical cancer for women using oral contraceptives, while laboratory results have shown that vaginal spermicides inactivate various sexually transmissible agents. To determine the role of contraceptive use in cervical cancer, 153 cases of Maryland women with invasive cervical cancer and age, race, and residence-matched controls were interviewed in 1985, focusing on sexual history, health care utilization patterns, screening history, contraceptive use, and smoking. Overall, lifetime use of contraceptives was protective of cervical cancer (odds ratio (OR) = 0.38, 95% confidence interval (CI) = 0.2-0.7). Use of oral contraceptives (OR = 0.48), diaphragm (OR = 0.29), and vaginal spermicides (OR = 0.28) were more frequent in controls than cases. After adjustment for behavioral factors (age at first intercourse, smoking, gaps in Papanicolaou smear testing, and obstetrician-gynecologist visits), use of vaginal spermicides remained significant (OR = 0.30), although use of oral contraceptives and barrier methods of contraception failed to remain significant. The effectiveness of vaginal spermicides in preventing cervical cancer may be due to their antiviral action.