Objective: to analyze the perceptions of student leaders of the undergraduate course in Nursing about the motivations and/or risk factors for substance use in the university environment. Method: qualitative, transversal, descriptive study developed in a university campus in the state of São Paulo. Thirty members of associations affiliated with the course in Nursing participated. A questionnaire and a semi-structured interview were used, and the information was subjected to content analysis. Results: the influence of the social environment was the central element in the results. The circumstances of the context, some conditions that favor the use of substances and the students’ expectations regarding their use were perceived as risk factors, among which the influence of friends (96%), curiosity and search for fun (93%) stood out. Final considerations: alternatives in the university context, in conjunction with student leaders, aimed at reducing the exposure to physical and psychological suffering, constitute important resources to prevent substance abuse.