Introduction Contingency management (CM) is efficacious for smoking cessation. To date, the number of cost-effectiveness evaluations of behavioral and pharmacological smoking cessation treatments far outnumbers the ones on CM. This study estimated 1-year efficacy and incremental cost-effectiveness of adding CM in relation to abstinence outcomes for a cognitive-behavioral therapy (CBT)+ behavioral activation (BA) treatment. Methods The study sample comprised 120 smokers with depression (% females: 70.8%; mean age: 51.67 SD= 9.59) enrolled in an 8-week randomized controlled clinical trial. Clinical effectiveness variables were point-prevalence abstinence, continuous abstinence, longest duration of abstinence (LDA), and Beck-Depression Inventory-II (BDI-II) scores at 1-year follow-up. Cost-effectiveness analyses were based on resource utilization, unit costs per patient, and incremental cost per additional LDA week at 1 year. Results There was a significant effect of time by treatment group interaction, which indicated superior effects of CBT+ BA+ CM across time. Point-prevalence abstinence (53.3% 32/60) was superior in participants receiving CBT+ BA+ CM compared with those in CBT+ BA (23.3% 14/60), but both groups were equally likely to present sustained reductions in depression. The average cost per patient was€ 208.85 (US 236.57)forCBT+BAand€410.64(US 465.14) for CBT+ BA+ CM, p<. 001. The incremental cost of using CM to enhance 1-year abstinence by one extra LDA week was€ 18 (US 20.39)(95%confidenceinterval:17.75–18.25).ConclusionsBehavioraltreatmentsaddressingbothsmokinganddepressionareefficaciousforsustaininghighquitratesat1year.AddingCMtoCBT+BAforsmokingcessationishighlycost-effective,withanestimatednetbenefitof€4704(US 5344.80). Implications Informing on the cost-effectiveness of CM might expedite the translation of research findings into clinical practice. Findings suggested that CM is feasible and highly cost-effective, confirming that its implementation is worthwhile. At a CM cost per patient of€ 410.64 (US 465.14),thenetbenefitequals€4704(US 5344.80), although even starting from a minimum investment of€ 20 (US 22.72)wascost-effective.ClinicalTrials-govIdentifierNCT03163056.