In an attempt to assess the multifocal nature of anogenital HPV infection in men, skin biopsies, urethral swabs and urine specimens were obtained from 100 men with genital dermatoses. The specimens were examined for the presence of human papillomavirus (HPV) types 6, 11, 16, 18, 31 and 33 using the polymerase chain reaction and Southern blotting techniques. HPV DNA was detected in one or more specimens from 39 patients, that is 29 of 100 biopsy specimens, 21 (25%) of 85 urethral swab specimens and 6 (10%) of 59 urine specimens. HPV DNA was more common in men with at least 20 lifetime sexual partners and in those who gave a history of anogenital warts. Twelve (18%) of 66 biopsy specimens with no histological evidence of warty change or neoplasia had detectable HPV DNA. HPV DNA was detected no more frequently in the urethral and urine specimens from men with histological evidence of warts or neoplasia than from men without such changes. HPV types 6 and 11 were most common in biopsy specimens with histological changes of typical HPV infection. HPV type 16 was commonest in biopsy specimens with neoplasia and type 18 with other changes. Furthermore, 'high-risk' HPV types were found proportionately more often in urethral swab and urine specimens than in biopsy specimens. There was generally a poor correlation between the detection of HPV DNA at the different sites. A greater understanding of the role of HPV in the production of genital abnormalities is required in order to develop a rational approach to the management of these patients.