目標：台灣地區於2005年8月引進美沙酮替代療法（Methadone Maintenance Treatment, MMT），目前是我國防制一級毒品之重要策略。但在引進替代療法後，截至2010底毒品人口並未明顯降低，再犯率亦未有效改善。原因究竟是替代療法療效不佳？或推行仍不普遍？本研究進行大範圍實證研究，以事實數據作為毒品政策成效檢驗之客觀參考。方法：本研究採非實驗設計研究方法，以2009年上半年出監的一級毒品毒癮者3343人為研究對象，以實際資料庫比對分析之計量方法為主，文獻探討為輔。樣本分為持續接受MMT療法與未接受MMT療法2組，分別追蹤18個月。結果：研究發現持續接受MMT療法組再涉毒品案件比率為30.57%。未使用MMT組為42.03%，效果顯著（P值為0.0084）。在降低財產、暴力再犯率亦呈現效果。惟樣本中替代療法涵蓋率僅19.86%，參加替代療法者在18個月後維持率僅23.64%，對整體再犯率改善之影響有限。結論：MMT療法經證實具有降低再犯毒品效果但留置率低，且在治療初期降低再犯毒品之效果並不顯著，其執行方式之妥適性待進一步探究。 Objectives: In August 2005, the Taiwanese government introduced Methadone Maintenance Treatment (MMT), one of the major strategies in fighting drug abuse; however, as of 2010, the MMT strategy still had not demonstrated effectiveness in reducing the addicted population or the recidivism rate. The aims of this study were to determine whether MMT was effective in Taiwan and to provide objective evidence to authorities before more resources were invested in this protocol. Methods: This study used a non-experimental design approach. A total of 3343 drug abusers released from correctional facilities during the first half of 2009 were divided into adaptive and non-adaptive MMT groups. Follow-up observation was done over 18 months and included drug recidivism and both property and violent crimes for each group. Results: The drug recidivism rate for the MMT group was 30.57%, whereas that for the non-MMT group was 42.03%. The lower rate of the MMT group was expected, but the efficacy of MMT was not evident at the 6- and 12-month observational periods. Only 23.64% of the addicts remained in MMT therapy. Conclusions: The adequacy of MMT implementation and its supporting measures in Taiwan must be further examined.