The incidence of new AIDS diagnoses among gay males indicates that risk reduction in smaller communities may be lagging behind that reported in larger cities. Contradictory evidence exists, largely from urban areas, concerning the utility of HIV testing as a means of promoting behavioural change. This study examined the relationship between HIV antibody testing and subsequent high-risk sexual behaviours among gay men in cities of 180,000 or fewer inhabitants. In February and March of 1992, male gay bar patrons in sixteen small US cities were administered an anonymous questionnaire concerning recent sexual behaviour and HIV testing history. Of the 1820 respondents, 28.1% had recently engaged in unprotected anal intercourse and 60.7% had been tested for HIV antibodies. Those who had been tested were more sexually active and reported more protected and safer sexual activities. Analyses at the individual and city levels converged to demonstrate that communities as well as individuals evidence increased self-protection in association with HIV antibody testing.