Objectives: The risk of sexually transmissible infection (STI) among sex workers and their clients may be higher than the general population. However, many studies have categorised workers or clients into homogenous groups for the purposes of analysis. The aim of the present study was to assess variations in self-reported STI rates among licenced brothel, private and illegal sex workers and their clients. Methods: In 2003, self-report data were collected from female sex workers and their male commercial clients residing in the state of Queensland, Australia. Overall, 247 sex workers (aged 19–57 years) and 185 of their respective clients (aged between 19 and 72 years) completed anonymous questionnaires. Results: There was little variation in self-reported lifetime STI prevalence of licenced brothel, private and illegal (predominantly street-based) sex workers, although licenced brothel workers were less likely to report ever being diagnosed with gonorrhoea or pubic lice in the past (P = 0.035 and 0.004 respectively). In contrast, clients accessing illegal services reported higher lifetime STI (36.0%, 95% confidence interval (CI) 20.2–55.6) than men recruited through private sex workers (20.0%, 95% CI 11.4–32.5) and clients from licenced brothels (7.6%, 95% CI 3.7–14.5). Conclusions: This study found high self-reported lifetime prevalence of infection among sex workers and their clients. It is notable, however, that lower STI rates were reported by clients and sex workers from licenced brothels. This would suggest that risk of infection is not equivalent across industry sectors and highlights some of the inherent risks associated with generalisation across the sex industry.