As part of a study to develop effective Internet-based HIV prevention interventions for Men who use the Internet to seek Sex with Men (MISM), we sought information from the target population on; (a) acceptability of sexually explicit media; (b) interest in specific content areas; and (c) identification of credible sources of information. A cross-sectional stratified Internet-based survey design was employed. Between September and November 2005, we recruited 2,716 MISM through Gay.com stratified across race/ethnicity to ensure adequate racial/ethnic diversity. Sixteen Likert-type items assessed acceptability of sexual explicitness, 24 items identified topics for inclusion, and two assessed sources of information. There was near universal acceptability for highly sexually explicit education. Over 75% reported high interest in 10 sexual health topics. HIV positive MISM and MISM engaged in unprotected anal sex with multiple male partners reported significantly less interest in HIV prevention specific content. Differences across age, race/ethnicity and education were identified. Idiosyncratic searches and gay sites were frequently cited sources of information; however blogs, government, and media sites were not. It is acceptable for web-based HIV prevention for MISM to be highly sexually explicit and to provide detailed content relevant to men's sexual health. Since demographic differences in acceptability and content were minor, it is appropriate for interventions to target across demographics. Interventions to re-engage men engaging in high risk and HIV + MISM should be considered. Leading health agencies should review whether their web information is retrievable, credible and useful to those most at risk.