This cross-sectional study examined OC traits and obsessive-compulsive gambling tendencies as predictors of gambling behaviours among 3,712 Nigerian undergraduates. Participants completed measures including an adapted Yale-Brown Obsessive Compulsive Scale (for gambling-related obsessions/compulsions), the Problem Gambling Severity Index (PGSI), and items on gambling frequency, expenditure, and risky behaviours (e.g., chasing losses).Hierarchical multiple regression analyses, controlling for age, gender, impulsivity, anxiety, and substance use, showed that higher OC traits significantly predicted elevated PGSI scores and greater risky gambling engagement (β = 0.28–0.41, p < 0.001). Compulsive gambling features (e.g., persistent urges, preoccupation) partially mediated this relationship. Stronger obsessive-compulsive gambling patterns were linked to increased time and money spent gambling, beyond impulsivity effects. Findings position OC traits as a vulnerability factor for problematic gambling, supporting early screening in student populations and targeted cognitive-behavioural interventions addressing compulsivity and gambling urges.