Combining drug abuse and HIV risk reduction counseling with opioid agonist maintenance treatment (OMT) or antagonist maintenance treatment with naltrexone (NMT) is effective for reducing illicit drug use and preventing HIV transmission associated with heroin dependence, but support for NMT and OMT remains tenuous in many Western Pacific countries (e.g., Malaysia, Indonesia and Singapore) where heroin addiction and HIV infection are epidemic and closely linked due to injection drug use (IDU) and high-risk sexual behaviors among addicts. Promising results of NMT in Malaysia have created interest in evaluating OMT using buprenorphine (BMT) and comparing the efficacy of counseling alone and counseling combined with BMT or NMT. This 24-week, randomized double blind clinical trial compares the efficacy for preventing heroin use and relapse and reducing HIV risk behaviors of manual-guided, HIV risk reduction and drug counseling (DC-HIV) alone or when combined with buprenorphine maintenance treatment (BMT) or naltrexone maintenance treatment (NMT) for recently detoxified and currently abstinent heroin dependent patients (N=180) in Malaysia (Specific Aim 1). The study will allow evaluation of 3 hypotheses: DC-HIV plus naltrexone is superior to DC-HIV alone; DC-HIV plus buprenorphine is superior to DC-HIV alone; and DC-HIV plus naltrexone is superior to DC-HIV plus buprenorphine. Primary outcome measures, assessed by 3x/wk urine toxicology testing and self-report, include resumption of heroin use, 1 or 3 weeks continuous relapse and reductions in HIV risk behaviors. The project will also evaluate the characteristics of treatment-seeking heroin addicts in Malaysia (including specific risk behaviors and patterns of HIV risk behaviors; prevalence of psychiatric and other medical comorbidity; and patterns of social, family, vocational, and criminal activity and service needs—Specific Aim 2). This data will be used to revise the DC-HIV manual to address the specific circumstances and risk behaviors of Malaysian heroin addicts. Finally, the project provides clinical training for health professionals and training and mentoring in drug abuse treatment and HIV prevention research to clinical researchers who will continue development, implementation, evaluation and dissemination of HIV prevention and drug abuse treatment approaches in Malaysia after the project ends (Specific Aim 3). The results of the study will inform government policy and support for HIV prevention and drug abuse treatment efforts in Malaysia and possibly also in other Western Pacific countries.