The objectives of this study were to determine whether the risk profiles of chlamydia-infected men in a clinical setting differ based on their symptom status. In all, 363 heterosexual, chlamydia-infected men attending a Sydney sexual health service were compared with controls. The 172 asymptomatically infected men and the 183 symptomatically infected men were also compared with the controls, and with each other. Compared with symptomatic men, asymptomatically infected men were younger (P = 0.03), and more likely to be overseas-born (adjusted odds ratio (AOR) 2.0, 95% confidence interval [CI] [1.1-3.5]), to be in a relationship (AOR 2.4, 95% CI [1.4-4.0]), to report contact with a chlamydia-infected woman (AOR 3.7, 95% CI [2.0-7.1]) and to have had contact with a partner with a non-chlamydial infection (AOR 10.7, 95% CI [1.3-89.7]). Infected men with a history of chlamydia were more likely to have current symptoms and a shorter duration of those symptoms. In conclusion, in a clinical setting, there appear to be differences in the profiles of symptomatic and asymptomatic chlamydia-infected men.