BACKGROUND:There has been a call for comprehensive cancer care that gives greater consideration to changing lifestyle risk factors such as smoking to improve prognosis and long-term health. Cancer diagnosis, treatment, and survivorship offer challenges and opportunities ("teachable moments") to promote smoking cessation. METHODS:This review provides a rationale for the importance of smoking cessation programs in the cancer context, highlights practice guidelines for the delivery of these interventions, summarizes the challenges to smoking cessation unique to cancer patients, and recommends approaches to capitalize on the cancer context to promote smoking cessation. RESULTS:Barriers to smoking cessation by patients with cancer include heavy nicotine dependence, urgency of cessation, fatalistic attitudes about cessation benefits, cancer-related psychological distress, treatment factors, and the presence of smokers in the social network. Opportunities to promote cessation include the transition from inpatient to outpatient care, involvement in cancer patient care by family members who smoke, and distribution of clinical feedback (eg, test results). CONCLUSIONS:Teachable moments in the cancer context are not being fully utilized to promote smoking cessation. Evidence-based guidelines can assist cancer care teams in promoting cessation.