Condom use is the best available strategy to prevent HIV infection during sexual intercourse. However, since many people choose not to use condoms in circumstances in which HIV risk exists, alternatives to condom use for HIV prevention are needed. Currently there are several alternative bio-medical HIV-prevention products in different stages of development: microbicides, vaccines, post-exposure prophylaxis (PEP) and pre-exposure prophylaxis (PrEP). Seventy-two men who have sex with men (MSM) who took part in a study on Internet use and intentional condomless anal intercourse were asked about these four products during a semi-structured interview. The questions explored knowledge and acceptability of all the products and willingness to participate in microbicide and vaccine trials. Qualitative analysis of the data suggests that these men had virtually no knowledge of PrEP, very limited knowledge of microbicides, some information about PEP and considerably more knowledge about vaccines. Reactions towards the products were generally positive except for PrEP, for which reactions were polarized as either enthusiastic or negative. With the exception of PrEP, many men expressed willingness to use the products in the future. Most men would be willing to participate in trials for microbicides and vaccines if given basic reassurances. Concerns over negative side effects and preoccupation with possible infection were some of the motives given for non-willingness to participate in a vaccine trial. These results should inform the development of future trials of biomedical prevention products.