Lose weight. Quit smoking. Exercise more. For over a century, governments and voluntary groups have run educational campaigns encouraging Canadians to adopt healthy habits in order to prolong lives, cost the state less, and produce more efficient workers. Be Wise! Be Healthy! explores the history of public health in Canada from the 1920s to the 1970s. Through the Health League of Canada, people were urged to drink pasteurized milk, immunize their children, and avoid extramarital sex. Health was presented as a responsibility of citizenship – and doctors and dentists as expert guides. Public health campaigns have reduced preventable deaths. But such campaigns can also stigmatize marginalized populations by implying that poor health is due to inadequate self-care, despite clear links between health and external factors such as poverty and trauma. This clear-eyed study demonstrates that while we may well celebrate the successes of public health campaigns, they are not without controversy.