The study was aimed at determining the prevalence, pattern and factors associated with psychoactive substance use among medical students in the University of Ilorin, Nigeria. All consenting medical students were requested to compile a 22-item modified, pilot-tested semi- structured self-report questionnaire based on the World Health Organization's guidelines for student substance use survey. It was found that the most currently used substances were mild stimulants (33.3%), alcohol (13.6%), sedatives (7.3%) and tobacco (3.2%). Except for tobacco, the use of these substances seemed to be only instrumental. Substance use was directly associated with male gender, living alone, self-reported study difficulty, being a clinical student, and being aged 25 years or more. There was an inverse relationship of substance use with religiosity and good mental health.
Keywords: Nigeria; Psychoactive substance use; medical students.