STUDY OBJECTIVE:To assess the effect of patient smoking status on internists' inclinations to recommend certain types of therapy for conditions that are and conditions that are not related to smoking. DESIGN, SETTING, AND PARTICIPANTS:Five hundred ninety-eight internists identified systematically from the Directory of Medical Specialists (first entry on each page of text) were asked to complete a questionnaire about how their treatment decisions for five therapies differed as a function of patient smoking status. RESULTS:The responses of the 320 internists who completed and returned the questionnaire showed that smoking status had little effect on physicians' inclinations to recommend herniorrhaphy, hemodialysis, or bronchodilator therapy. However, physicians were considerably less inclined to recommend coronary artery bypass grafting or peripheral arterial surgery to patients who smoked. Reduced efficacy and greater risk of therapy were the most frequent reasons given for the observed decrease. Reduced entitlement by smokers to complex therapies for smoking-related diseases and the withholding of therapy as a bargaining tool to induce smokers to quit were also cited as reasons. CONCLUSIONS:Some internists believe they are less likely to recommend complex therapies for smoking-related diseases to patients who continue to smoke. Some of this decrease may be attributable to the notion that smokers are less entitled to complex therapies or that withholding therapies is a permissible way to influence patients to adopt more healthful lifestyles. Whether these physician attitudes reflect actual practice is yet to be shown.