The sample will be hospitalized patients smoking at least 10 cigarettes/day prior to hospitalization. Intention to quit smoking will not be required for study participation. Using a double-blinded, placebo-controlled, randomized design, participants will receive varenicline (0.5 mg BID as tolerated) or placebo during their hospitalization (Part 1) and will continue their study medication (placebo or active drug) for 4 weeks post-hospitalization (Part 2). Abstinence status will be examined at 4 weeks post-hospitalization.
