This prospective study examined the relationship between cigarette smoking and five-year substance abuse treatment outcomes. Of 749 individuals who began private outpatient treatment, 598 (80%) were re-interviewed by telephone at five years. At five-year follow-up, 53% reported smoking cigarettes in the prior 30 days. Smokers were less likely to be abstinent from alcohol and drugs in the prior 30 days (48.3% vs. 64.0%), and had higher Addiction Severity Index (ASI) scores in employment, alcohol, drug, psychiatric, and family/social problems; worse self-reported health; and greater self-reported depression. Findings inform understanding of long-term substance abuse treatment outcomes and potential service needs of smokers.