Background: Substance use by university students poses serious health and academic risks. Despite national concern, little is known about patterns and predictors of alcohol and drug use among young adults in Northeast India, whose socio-cultural influences differ from the rest of the country.

Objective: To assess the prevalence, patterns, and predictors of alcohol and drug use among undergraduate university students in Sonitpur, Assam.

Materials and Methods: A total of 404 students were selected using multi-stage stratified systematic sampling and participated in this cross-sectional survey. A sociodemographic sheet, AUDIT, and DAST-10 were used for data collection. Descriptive and multiple regression analyses were conducted.

Results: Most students were abstainers or low-risk drinkers (94.3%), with 4.7% reporting harmful use and 1% dependence on AUDIT. Drug use was similarly low, with 78.96% reporting no problems and 21.04% showing low-to-moderate involvement. Predictors of higher AUDIT scores included age, gender, education level, and poor sleep quality (R² = 0.108). Gender, family type, and academic stress significantly predicted DAST-10 scores (R² = 0.087).

Conclusion: Although overall substance use was low, a notable minority showed risk patterns. Predictors reflected individual, family, and sociocultural influences, pointing to the need for culturally tailored prevention and campus-based mental health initiatives in Northeast India.