ABSTRACT: BACKGROUND:Syphilis screening for men who have sex with men (MSM) in San Francisco (SF) is recommended every 3 to 6 months. We surveyed MSM in SF to determine the prevalence and factors associated with complying with that recommendation, identify screening barriers, and investigate whether identifying low perceived syphilis risk as a reason for not testing correlated with syphilis risk factors. METHODS:We conducted a cross-sectional survey as part of the National HIV Behavioral Surveillance System. We used logistic regression to analyze factors associated with complying with the SF-specific screening recommendation and with identifying low perceived risk as a reason for not testing. We analyzed data on screening barriers descriptively. RESULTS:Among 441 MSM, 37.5% (95% confidence interval [CI], 31.5%-43.6%) complied with the recommendation. Compliance was associated with human immunodeficiency virus infection (odds ratio [OR], 3.6; 95% CI, 1.7-7.8), more than 10 male sex partners (OR, 4.3; 95% CI, 1.6-12.0), having unprotected anal sex with a casual partner (OR, 4.2; 95% CI, 2.0-8.9), and knowing the recommendation (OR, 4.1; 95% CI, 2.1-8.2). Low perceived risk, time constraints, and not knowing that one should get screened were identified as reasons for not testing by 61.7%, 18.9%, and 18.8%, respectively. Identifying low perceived risk as a reason for not testing was associated with having more than 10 sex partners (OR, 0.2; 95% CI, 0.1-0.5). CONCLUSIONS:Attempts to improve compliance with the syphilis screening recommendation should include education regarding recommended screening frequency and syphilis risk factors and interventions to increase screening convenience.