 Experimental design and methods. The study will be a randomized double-blind clinical trial. Two treatment groups will be studied 60group, one receiving clonidine and the other receiving placebo. Assignment to treatment group will be randomized. All patients will receive buprenorphine daily 8 mg to 24 mg SL and individual counseling weekly throughout 28 weeks of treatment. In order to establish abstinence prior to clonidine induction, after one week of stabilization on buprenorphine, they will receive contingent vouchers for opioid-negative urine specimens for 8 weeks weeks 1-8. Patients who are abstinent from illicit opioids during weeks 5 and 6 will be randomized to receive clonidine 0.3 mg oral dose or clonidine placebo from weeks 9 through 20. Participants who are not abstinent will be switched to methadone for four weeks usual dose from 50 mg to 100 mg followed by an eight week methadone taper. Assignment to clonidine or placebo will be double-blind. Weeks 21 and 22 will include a clonidine taper to avoid rebound hypertension. From weeks 23-28, participants will receive buprenorphine and counseling only, and then will be offered assistance to transfer to another program; those who do not transfer will undergo an 8-week buprenorphine taper. The primary outcome measures will be longest duration of opioid abstinence, time to relapse, and the proportion of opioid-negative urine specimens over time during the Intervention phase. In addition, fluctuations in drug use, drug craving, stress, and HIV-risk behaviors such as injection drug use will be assessed via ecological momentary assessment EMA. 