Drug-involved smokers may be less motivated to quit smoking because they expect smoking cessation to occasion adverse outcomes (e.g., exacerbation of drug use). Non-treatment-seeking adult smokers from the community (. N=. 507) reported drug involvement, expectancies for smoking abstinence via the Smoking Abstinence Questionnaire (SAQ), and motivation to quit smoking (desire to quit and abstinence goal). Mediation analyses evaluated the indirect effects of binge drinking, marijuana, cocaine, other stimulant, opiate, and barbiturate/other sedative involvement on motivation to quit smoking through the SAQ Adverse Outcomes scale. Adverse outcomes expectancies accounted for a reduced desire to quit smoking and a lower likelihood of endorsing a goal of complete smoking abstinence among those involved with binge drinking, marijuana, cocaine, other stimulants, opiates, and barbiturates/other sedatives. Drug-involved smokers' greater expectancies for adverse outcomes upon quitting smoking may deter smoking quit attempts. Interventions are encouraged to counteract the notion that smoking cessation jeopardizes sobriety. © 2014 Elsevier Inc.