Large studies of genital human papillomavirus (HPV) infection in men are few and mainly include high-risk groups. We interviewed 779 men who requested a vasectomy in 27 public clinics in 14 states of Mexico. Exfoliated cells were obtained from the scrotum, the shaft of the penis, the top of the penis including the coronal sulcus, the glans and the opening of the meatus. HPV testing was performed using biotinylated L1 consensus primers and reverse line blot. Unconditional logistic regression was used to estimate odds ratios (ORs) of being HPV-positive and corresponding 95% confidence intervals (CIs). The prevalence of any type of HPV was 8.7%. HPV positivity was highest among men below age 25 (13.6%), and lowest among men aged 40 years or older (6.0%). The most commonly found HPV types were, in decreasing order, HPV59, 51, 6, 16 and 58. Lifetime number of sexual partners was associated with HPV positivity (OR for 4 vs. 1 partner 5 3.7, 95% CI: 2.0-6.8), mainly on account of the strong association with number of occasional and sex-worker partners. Condom use with both regular (OR 5 0.4, 95% CI: 0.1-1.0) and sex-worker (OR 5 0.1, 95% CI: 0.0-0.3) partners and circumcision (OR 5 0.2, 95% CI: 0.1-0.4) were inversely associated with HPV positivity. HPV prevalence in Mexican men was similar to the prevalence found in Mexican women of the same age groups. The association between HPV positivity and lifetime number of sexual partners in the present low-risk male population is one of the strongest ever reported in studies in men. Condom use and circumcision were associated with a strong reduction in HPV prevalence. ' 2006 Wiley-Liss, Inc.Key words: human papillomavirus; men; Mexico; sexual habits; condom use Human papillomavirus (HPV) infection, the necessary cause of invasive cervical cancer and its precursor lesions, 1 is a very common sexually transmitted disease in women in many populations. 2 HPV infection in men causes genital warts, 3 and is associated with HPV infection 4,5 and cervical cancer 6,7 in female partners.Previous studies on genital HPV infection in men showed an approximately equal prevalence of HPV infection in any population in the 2 genders, 8 and the existence of a direct, though moderate, association between HPV positivity among men and lifetime number of sexual partners. 9,10 However, contrary to the relatively large amount of information on genital HPV infection in women, 2,11 large studies on HPV prevalence in the general male population are few. Furthermore, the majority of studies in men have focused on young individuals 12 or high-risk populations [e.g., men attending sexually transmitted disease (STD) clinics 9,13,14 or enrolled in military service [15][16][17] ].Two previous reports from Mexico 12,17 showed that more than one-third of the young men studied were infected with genital HPV. To further elucidate the characteristics of HPV infection in the general male population, we assessed the prevalence and determinants of infection with 35 HPV types among 779 Mexican men who attended publi...