Background: Human immunodeficiency virus (HIV) infection predisposes women to genital coinfection with human papillomaviruses (HPVs). Concurrent infection with multiple HPV types has been documented, but its frequency, correlates, and impact on development of precancer are poorly defined in HIV-seropositive women. Methods: Human immunodeficiency virus-seropositive women and-seronegative comparison women were enrolled in a cohort study and followed every 6 months from 1994 to 2006. Cervicovaginal lavage samples were tested for HPV types using polymerase chain reaction amplification with MY09/MY11 consensus primers followed by hybridization with consensus and HPV type-specific probes. Analyses were performed using generalized estimating equations. Results: Multitype HPV infections were found in 594 (23%) of 2543 HIV-seropositive women and 49 (5%) of 895 HIV-seronegative women (P < 0.0001). Compared with HPVuninfected women, those with multiple concurrent HPV infections were more likely to be younger, nonwhite, and current smokers, with lower CD4 counts and HIV RNA levels. The average proportion of women with multitype HPV infections across visits was 21% in HIV-seropositive women and 3% in HIV-seronegative women (P <0.0001). Compared with infection with 1 oncogenic HPV type, multitype concurrent infection with at least 1 other HPV type at baseline did not measurably increase the risk of ever having cervical intraepithelial neoplasia 3+ detected during follow-up (odds ratio, 0.80; 95% confidence interval, 0.32-2.03, P = 0.65). Conclusions: Concurrent multitype HPV infection is common in HIVseropositive women and frequency rises as CD4 count declines, but multitype infection does not increase precancer risk.