To identify factors associated with persistence of human papillomavirus (HPV) DNA in the uterine cervix, 179 women who were 18-49 years old and who had normal cytologies and positive cervical HPV DNA test at a routine periodic examination were analyzed. Among them, 91 (50.8%) remained HPV-positive a few months (mean, 11 weeks) later. Persistence was higher in women who had used oral contraceptives for > or = 2 years (odds ratio, 3.9; 95% confidence interval, 1.5-10.3) compared with those who never used oral contraceptives or used them for <2 years. HPV types 16, 18, and 31/33/35 appeared more persistent (odds ratio, 2.5; 95% confidence interval, 1.0-6.2) than other types. Persistence seemed to increase with virus load and decrease with increasing interval between examinations.