TB is concentrated in populations with complex health and social issues, including alcohol use disorders (AUD). We describe treatment adherence and outcomes in a person-centred, multidisciplinary, psychosocial support and harm reduction intervention for people with multidrug-resistant or rifampicin-resistant TB (MDR/RR-TB) with harmful alcohol use. An observational cohort study, including multilevel mixed-effects logistic regression and survival analysis with people living in Minsk admitted with MDR/RR-TB and AUD during January 2019-November 2021 who received this person-centred, multidisciplinary, psychosocial support and harm reduction intervention, was conducted. There were 89 participants enrolled in the intervention, with a median follow-up of 12.2 (IQR: 8.1-20.5) mo. The majority (n=80; 89.9%) of participants had AUD, 11 (12.4%) also had a dependence on other substances, six (6.7%) a dependence on opioids and three (3.4%) a personality disorder. Fifty-eight had a history of past incarceration (65.2%), homelessness (n=9; 10.1%) or unemployment (n=55; 61.8%). Median adherence was 95.4% (IQR: 90.4-99.6%) and outpatient adherence was 91.2% (IQR: 65.1-97.0%). Lower adherence was associated with hepatitis C, alcohol plus other substance use and outpatient facility-based treatment, rather than video-observed treatment, home-based or inpatient treatment support. This intervention led to good adherence to MDR/RR-TB treatment in people with harmful use of alcohol, a group usually at risk of poor outcomes. Poor outcomes were associated with hepatitis C, other substance misuse and outpatient facility-based treatment support.