OBJECTIVES:To assess what family physicians need to promote smoking cessation by looking at current knowledge, attitudes, and behaviours and to examine the barriers facing physicians in implementing an effective antismoking strategy. DESIGN:Cross-sectional study involving face-to-face interviews and mailed questionnaires. SETTING:Family practices in Kingston, Ont, and surrounding areas. PARTICIPANTS:All family physicians (n = 155) in the City of Kingston and the counties of Frontenac, Lennox, and Addington. MAIN OUTCOME MEASURES:Knowledge, attitudes, beliefs, and practices concerning smoking cessation; barriers and practices recommended in the literature. RESULTS:Response rate was 77%. Many physicians know about smoking cessation, and many actively counsel their patients to quit. Brief advice, nicotine replacement therapy, self-help materials, and follow-up appointments are the most common methods. Although many report that they are already knowledgeable, many are willing to learn more. Many physicians have unrealistically high estimates of the probability of success, and many find poor compliance among patients to be the greatest barrier. CONCLUSIONS:Family physicians in this are recognize the need to help their patients to quit and are identifying and counseling smokers in their practices. The main educational need could be to appreciate smoking as an addictive behaviour.