OBJECTIVE: To review the literature about cycling and health, and to provide an overview and discussion of the available evidence. SOURCES OF INFORMATION: The MeSH terms bicycle and transportation were searched in PubMed. Clinical trials, practice reviews, and systematic reviews were included. All reference lists were reviewed for additional articles. MAIN MESSAGE: Climate change is a threat to health. In Canada alone, transportation is the second largest source of greenhouse gas emissions. Active transportation, which is any form of human-powered transportation, can mitigate the health effects of the climate crisis while simultaneously improving the health of people. Physical activity improves overall well-being, as well as physical and mental health. Active transportation, particularly cycling, is a convenient way to meet physical activity targets, reduce risk of disease and all-cause mortality, and derive mental health and social benefits. Family physician advocacy for active transportation has been shown to increase cycling levels in patients compared with no physician advocacy. CONCLUSION: Family physicians can help to increase the level of active transportation at the individual patient level through patient education and behaviour change counseling; at the community level through community education and political advocacy; and at the policy level through partnerships with larger organizations.