An ethnically diverse sample (69.7% men of colour) of HIV-seropositive MSM from the New York City and San Francisco metropolitan areas were recruited from a variety of social settings. While only 27.0% of the participants were recruited from PSEs (public sex environments where men 'cruise' for potential sex partners, such as parks) and CSEs (commercial sex environments where an admission is paid for entrance, such as bathhouses and sex clubs), 49.6% reported attending PSEs and 40.7% reported attending CSEs. Only a minority of participants from the full sample reported sexual behaviours that would have placed a partner at highest risk for HIV seroconversion. However, differences between those who frequented CSEs and those who did not emerged on several psychosocial factors (sexual sensation seeking, depression, perceived responsibility towards protecting sexual partners from HIV infection), sexual risk behaviours (unprotected oral and anal sex) and types of recreational drugs used. Fewer differences were found between those who frequented PSEs and those who did not.