Smoking among patients with mental illness is a major and underappreciated public health problem. The case of Ms G, a 51-year-old woman with bipolar disorder who wishes to quit smoking, illustrates the importance and feasibility of smoking cessation in patients with psychiatric disorders. Persons with chronic mental illness and/or substance abuse constitute 22% of the US population yet are estimated to consume 44% of cigarettes. As many as 200 000 of the 435 000 annual deaths related to smoking in the United States are estimated to occur in this population. On average, patients with mental illness die 25 years earlier than the general population, and smoking is a major contributor to these premature deaths. In the past, mental health clinicians have tended not to address smoking cessation with their patients, but increasing evidence suggests that such reticence is unwarranted, as smoking cessation in this population is feasible. The approach to cessation should include standard interventions of counseling and pharmacotherapy, for which substantial evidence of efficacy exists in patients with and without mental illness. If patients with mental illness are to achieve wellness, smoking cessation must be an integral component of their treatment regimen.