In the fall of 2009, Canada undertook a mass vaccination campaign against pH1N1. This report provides an overview of self-reported pH1N1 vaccination coverage of the Ontario population, building on an existing random digit-dialling telephone survey, in which 9,010 Ontario adults participated. Based on the results, 34.5% of Ontario residents were vaccinated: 33.3% of adults aged 18 or older and 38.6% of children and adolescents younger than age 18. Respondents reporting high-risk chronic conditions were significantly more likely to report being vaccinated than were people who did not report such conditions. Determining vaccination uptake for the Ontario population is important in the evaluation of the province's pH1N1 prevention program.