OBJECTIVE Alcoholic liver cirrhosis (ALC) is an established indication for liver transplantation (LT). Although the importance of preoperative abstinence is accepted, the optimal period of pretransplant abstinence is unclear. Our previous report in a Japanese cohort revealed a significant negative impact of recidivism on patient survival but failed to show significance of the length of pretransplant abstinence. The aim of this study was to evaluate the optimal period of pretransplant abstinence. METHODS Subjects underwent LT for ALC (n = 195: 187 living donor liver transplantations, five deceased donor liver transplantations and three domino LT) in Japan from November 1997 to December 2011. Risk factors and the impact on outcome of alcohol relapse were analyzed in 140 patients, after excluding 26 patients with in-hospital mortality and 29 patients without information about alcohol relapse. RESULTS The incidence of alcohol consumption after LT was 22.9% (32/140). The relapse time was within 18 months after LT in 24 patients, after 18 months in two patients and unknown in six patients. Alcohol-related damage occurred in 18 of the 24 patients with recidivism within 18 months. The patient survival rate of patients with harmful relapse was significantly lower than that of abstinent patients and patients with non-harmful relapse (P = 0.019). Preoperative abstinence shorter than 18 months was a significant indicator of the risk of harmful relapse (P = 0.009). High-risk alcohol relapse scores had no impact on the incidence. CONCLUSIONS Preoperative abstinence was an important predictor of post-transplant harmful relapse leading to inferior outcomes.