This is a randomized, double blind placebo-controlled trial to examine the role of Relapse Prevention (RP) and Contingency Management (CMP) combined with Naltrexone (NTX) for the treatment of cocaine-alcohol dependence. Patients will be randomly assigned to NTX (100mg/d) or placebo combined with one of two psychotherapy conditions (RP or RP +CMP). Following a standardized consent and intake procedure patients will participate in a 12-week trial with thrice weekly visits. Manual-guided RP therapy will be delivered in weekly 60-minute individual sessions. CMP will be based on cocaine-negative urine screens and negative breath alcohol tests. Follow-up assessments will be conducted at 3 and 6 months after treatment.