In an attempt to better understand deterrents to donating blood, almost 2,000 blood donors in Quebec were surveyed.Although answers varied based on sex, age and level of education, time constraints were the largest deterrent to donating blood, with work and study being the most cited reasons (43% of all respondents). Furthermore, heath concerns deterred 39% of lapsed donors from donating, predominantly among female donors and those with lower education levels. Differences were also noted by age group. People in their 20s were more likely to cite time constraints, travel, and moving, those in their 30s often noted pregnancy and family responsibilities, and those over 40 years old were more likely to cite health problems. Blood collection agencies should tailor donor retention strategies based on sex, age and level of education.