Given high rates of smoking among cancer patients, smoking cessation treatment is crucial; yet limited data exist to guide integration of such trials into the oncologic context. In order to determine the feasibility of conducting smoking cessation clinical trials with cancer patients, screening and baseline data from a large randomized placebo-controlled pharmacotherapy trial were analyzed. Descriptive statistics and regression analyses were used to compare enrollees to decliners, describe program enrollees, and assess correlates of confidence in quitting smoking. Out of 14,514 screened patients, 263 (<2%) were eligible; 43 (16%) refused enrollment. Among the eligible patients, 220 (84%) enrolled. Enrollment barriers included smoking rate, medical history/contraindicated medication, lack of interest, and language. Compared to enrollees, decliners were more likely to have advanced cancer. The trial enrolled a sample of 67 (>30%) African Americans; participants had extensive smoking histories; many were highly nicotine dependent; and participants consumed about seven alcoholic beverages/week on average. Head and neck and breast cancer were the most common tumors. About 52 (25%) reported depressive symptoms. A higher level of confidence to quit smoking was related to lower depression and lower tumor stage. Integrating a smoking cessation clinical trial into the oncologic setting is challenging, yet feasible. Recruitment strategies are needed for patients with advanced disease and specific cancers. Once enrolled, addressing participant's depressive symptoms is critical for promoting cessation.