Combination of non-nicotine pharmacotherapies has been underexamined for cigarette smoking cessation. A randomized, double-blind, parallel-group double-dummy study evaluated two medications, bupropion (BUP) and naltrexone (NTX), in treatment-seeking cigarette smokers (N = 121) over a 7-week treatment intervention with 6-month follow-up. Smokers were randomized to either BUP (300 mg/day) + placebo (PBO) or BUP (300 mg/day) + NTX (50 mg/day). The primary outcome was biochemically verified (saliva cotinine, carbon monoxide) 7-day, point-prevalence abstinence. BUP + NTX was associated with significantly higher point-prevalence abstinence rates after 7-weeks of treatment (BUP + NTX, 54.1%; BUP + PBO, 33.3%), P = 0.0210, but not at 6-month follow-up (BUP + NTX, 27.9%; BUP + PBO, 15.0%), P = 0.09. Continuous abstinence rates did not differ, P = 0.0740 (BUP + NTX, 26.2%; BUP + PBO, 13.3%). Those receiving BUP + NTX reported reduced nicotine withdrawal, P = 0.0364. The BUP + NTX combination was associated with elevated rates of some side effects, but with no significant difference in retention between the groups.