In order to be effective, sexually transmitted infection (STI) testing should be comprehensive based on the clients' sexuality and risk practices. Using data from the Sydney Gay Community Periodic Survey, we explored trends in and factors associated with STI testing among gay men during 2003-2007. Among men who were not HIV-positive, 68% were tested for HIV in 2007. HIV testing was more common than STI testing and remained stable during 2003-2007. Use of swabs and urine samples increased significantly (P-trend<0.001 for each). However, until 2007, 33% of men were not tested. Sexual behaviours (higher number of partners, having casual partners and engaging in unprotected anal intercourse with them) were associated with STI testing. HIV-negative men were tested for STI less often than HIV-positive men (prevalence ratio=0.56; 95% CI: 0.47-0.68). STI testing among HIV-negative men has improved significantly but remains inadequate for STI control and HIV prevention. It should not be assumed that appropriate and comprehensive STI screening is always provided to clients.