There is little information on the private lives of women engaged in sex work, particularly how power dynamics within intimate relationships may affect intimate partner violence (IPV). Using baseline data of sex workers enrolled in a longitudinal cohort, "An Evaluation of Sex Workers' Health Access" (AESHA), the present study examined the association between sexual relationship power and IPV among sex workers in non-commercial partnerships in Vancouver, Canada. Pulweritz's Sexual Relationship Power Scale (SRPS) and The World Health Organization (WHO) Intimate Partner Violence against Women Scale (Version9.9) were used. Bivariable and multivariable logistic regression techniques were used to investigate the potential confounding effect of sexual relationship power on IPV among sex workers. Adjusted odds ratios (AOR) and 95% confidence intervals (CIs) were reported. Of 510 sex workers, 257 (50.4%) reported having an non-commercial intimate partner and were included in this analysis. In the past 6 months, 84 (32.7%) sex workers reported IPV (physical, sexual or emotional). The median age was 32 years, 39.3% were of Aboriginal ancestry, and 27.6% were migrants. After controlling for known confounders (e.g., age, Aboriginal ancestry, migrant status, childhood trauma, non-injection drug use), low relationship power was independently associated with 4.19 increased odds (95% CI: 1.93-9.10) and medium relationship power was associated 1.95 increased odds (95% CI: 0.89-4.25) of IPV. This analysis highlights how reduced control over sexual-decision making is plays a critical role in IPV among sex workers, and calls for innovation and inclusive programming tailored to sex workers and their non-commercial intimate partnerships.