To understand predictors of Canadian physicians' prevention counseling practices. A national mailed survey of a random sample of Canadian physicians conducted November 2007-May 2008. Primary care physicians (n=3213) responded to the survey (41% response rate); those with better personal health habits, female physicians, and physicians aged 45-64 years old were more likely to report "usually/always" counseling patients than did others, but there were no significant differences by province, origin of one's MD degree, or practice location. There was a clear and consistent relationship between personal and clinical prevention practices: non-smokers were significantly more likely to report counseling patients on smoking cessation; those who drank alcohol less frequently, drank lower quantities or binged less often were more likely to counsel on alcohol; those exercising more to counsel patients more about exercise; those eating more fruits and vegetables to counsel patients more often about nutrition; and those with lower weight were more likely to counsel about nutrition, weight or exercise. Physicians who strongly agreed or agreed that "they will perform better counseling if they have healthy habits" averaged higher rates of counseling (p < 0.001). Personal characteristics of Canadian physicians help predict prevention counseling. These data suggest that by encouraging physicians to be healthy, we can improve healthy habits among their patients--an innovative, beneficent, evidence-based approach to encouraging physicians to counsel patients about prevention.