In Taiwan, driving under the influence of alcohol (DUI) is deemed criminal and the offenders are subjected to fines and/or jail penalties when arrested. So far alcohol treatment has not been included in the intervention for DUI offenders despite alcohol use problem is rather common in this population and has been shown a contributing factor to the recurrences of DUI behaviors. In an anonymous survey, we found more than half first-time DUI offenders reported to have alcohol use disorder (AUD). Of note, the prevalence of AUD actually increases with the number of prior DUI convictions in repeat offenders. Since 2015, Taiwan Taipei District Prosecutors Office (TTDPO) has first collaborated with Taipei City Hospital (TCH) to establish an alcohol treatment program for DUI repeat offenders with AUD by adopting a multi-component approach that integrates education, brief intervention, medical consultation, and case management. In a one-year post-intervention follow-up study, we found adequate duration of alcohol treatment, particular ≧ 5 months, is a significant factor associated with a lower risk of recidivism. In a further attempt to examine the potential benefit of the joint legal-medical program, we followed   participants with 12-month, 6-month, and no treatment for two years, and found the re-offense rate was 12%, 19%, and 21%, respectively. The hazard ratio for re-offense was lower for the 12-month group than for the 6-month group (hazard ratio: 0.45; 95% confidence interval: 0.21–0.96). Survival analysis revealed that compared with non-intervention group, 12-month but not 6-month treatment group significantly reduced re-offense. We suggest the legal-medical joint intervention program for alcohol treatment reduced 2-year DUI re-offense, and longer duration of treatment is associated with lower rates. These results provide some insight on the design of a collaborative program between legal and medical systems to reduce DUI recidivism and improve mental health of DUI repeat offenders.