Attitudes about quitting cigarette smoking were assessed at admission to a substance abuse treatment program for homeless veterans. The majority were interested in quitting smoking, believed that inpatient drug/alcohol treatment was the best time to quit, and that quitting would not threaten their sobriety. Using cluster analysis, four subgroups of inpatients with different levels of interest, confidence, and motivation regarding quitting smoking were identified. Our inpatients' positive attitudes about quitting smoking stand in contrast with previously reported attitudes of many health professionals, and suggest that inpatient treatment could be an opportune time to provide stop-smoking interventions. Findings also suggest that different treatment approaches may be needed for subgroups of inpatients with varying attitudes about quitting.