OBJECTIVES: This paper examines unmet health care needs in one of Canada's most hard-to-reach populations, adult sex workers, and investigates whether their reasons for not accessing health care are different from those of other Canadians.METHODS: Data gathered in 2012-2013 from sex workers aged 19 and over (n = 209) in five Canadian census metropolitan areas (CMAs) were analyzed to estimate the perceived health, health care access and level of unmet health care needs of sex workers, and their principal reasons for not accessing health care. These data were collected using questions identical to those of the Canadian Community Health Survey (CCHS) Cycle 2.1, 2003. The results were compared with those of residents aged 19 and over in the same CMAs who had participated in the CCHS.RESULTS: Sex workers reported notably worse perceived mental health, poorer social determinants of health (with the exception of income) and nearly triple the prevalence of unmet health care needs (40.4% vs. 14.9%). Those with the greatest unmet health care needs in both groups were younger, unmarried or single and in poorer health, and reported lower income and a weaker sense of community belonging. Even without these within-group risk factors, sex workers were more likely to report unmet health care needs compared with CCHS respondents. Sex workers were also more likely to identify "didn't get around to it", "too busy", "cost", "transportation problems" and "dislike doctors/afraid" as reasons for eschewing care.CONCLUSION: Equity policies that reduce cost and transportation barriers may go some way in helping sex workers access needed health care. Qualitative research is needed to better understand the realities of sex workers' personal and work lives, including the degree of freedom they have in accessing health care when they need it, but also their experiences when they do manage to engage with the health care system. KEY WORDS: Social determinants of health; access to health care; sex workers; unmet health care needs; barriers La traduction du résumé se trouve à la fin de l'article.