Commercial sex workers (CSWs) are often portrayed as vectors of disease transmission. However, the role clients play in sexual risk taking and related decisionmaking has not been thoroughly characterized. In this study, participants were drawn from the Vancouver Injection Drug Users Study, a longitudinal cohort. Analyses were restricted to those who reported selling sex between June 2001 and December 2005. Using multivariate generalized estimating equation, the prevalence of and factors associated with being offered money for sex without a condom was evaluated. A total of 232 CSWs were included in the analyses, with 73.7 percent reporting being offered more money for condom non-use, and 30.6 percent of these CSWs accepting. Variables independently associated with being offered money for sex without a condom included daily speedball use [adjusted odds ratio (AOR) = 1.21, 95 percent confidence interval (CI): 0.23-0.62], daily crack smoking (AOR = 1.51, 95 percent CI: 1.04-2.19), daily heroin injection (AOR = 1.76, 95 percent CI: 1.27-2.43) and drug use and clients (AOR = 3.22, 95 percent CI: 2.37-4.37). Human immunodeficiency virus seropositivity was not significant (AOR = 0.98, 95 percent CI: 0.67-1.44). The findings highlight the role clients play in contributing to unprotected sex through economic influence and exploitation of CSW drug use. HIV serostatus has no bearing on whether more money is offered for sex without a condom. Novel interventions should target both CSW and clients. Table and references (Published Abstract)