This randomized clinical trial study was designed to demonstrate the pattern of Opioid Withdrawal signs and symptoms in three groups. Each group contains 30 patients which makes a total patient of 90. The patients were selected from admitted patients in toxicology ward and referred to Rehabilitation Center of Imam-Reza Hospital. The patients will be randomly assigned to receive Clonidine Abstinence Therapy for 10 days, Methadone Maintenance Therapy (MMT) for 45 days, or short-time detoxification with Methadone for 5 days. The withdrawal signs and symptoms including Pain, nausea and vomiting, muscle twitching, rhinorrhea, yawning, diaphoresis, tremor, lacrimation, agitation, muscle aches, bone pain, arthralgia, piloerection, pupil size, abdominal pain, diarrhea, anxiety, dysphoric mood, etc. were compared between the three groups.