Alcohol use disorder has been reported in patients undergoing bariatric procedures, but the pattern of alcohol consumption has not been evaluated. We investigated the prevalence, risk factors, and impact of binge drinking (BD) at the time of surgery and during follow-up. A prospective, longitudinal study of subjects undergoing bariatric surgery was included in the LABS-2 registry between 2006 and 2009. Participants with AUDIT questionnaire at the time of surgery and a minimum of 12 months follow-up were included. BD was defined as consuming ≥5 drinks on at least 1 occasion in the previous month. Liver biopsies were obtained during bariatric procedures in not all cases. Survival analysis was performed with the adjusted Cox regression model and competing risk. A total of 2257 subjects were included, with a median follow-up of 79 months. The prevalence of BD at time of surgery was 12%, and it raised up to 23% during follow-up. Patients with BD predominantly had a binge eating disorder (OR=1.35 [95% CI: 1.04-1.76]), regularly consumed fast food [OR=1.4 (95% CI: 1.07-1.85)] and used other drugs (OR=2.65 [95% CI: 1.74-4.04]). Within liver biopsies evaluation, BD showed higher hepatic iron deposits (OR=3.00 [95% CI: 1.25-7.21]). BD at the time of surgery was associated with a higher risk of BD during follow-up (OR=10.49 [95% CI: 7.86-14.00]) and long-term mortality (HR: 3.21 [95% CI: 1.67-6.18]). Specific causes of death in these patients with BD were liver disease (p=0.020), suicide (p=0.015), neoplasms (p=0.034), and respiratory (p=0.025). The prevalence of BD in patients undergoing bariatric surgery is high and increases the risk of postoperative liver disease, suicides, and long-term mortality.