Background: Recreational drug use among students in tertiary institutions remains a public health concern. Despite documentation of drug use in Kenyan universities, most of the studies are based on self reported history which is prone to social desirability bias. It is in this context that we sought to establish actual drug use among university students. Methods: We investigated self reported and confirmed drug use. Using proportionate to size and snowball sampling methods 380 respondents were enrolled. Social demographic characteristics and self reported drug use history were documented using a participant assisted questionnaire. Actual drug use was determined qualitatively using 6 panel plus alcohol SalivaConfirm™ Saliva Test kit. Results: Most (75%) of the participants were sexually active. Based on self reported history, 221 (58%) students reported a life time ever use of drugs while based on saliva testing (193) 51%) tested positive for at least one drug. Alcohol, tobacco products (cotinine), marijuana and amphetamine or khat were the most preferred drugs. The usage was either solely, concurrently or simultaneously. In the multivariate regression model, compared to students with no sexual partner having multiple sexual partners was associated with risk of testing positive for any drug: adjusted risk ratio (aRR) of 2.06 (95% CI 1.26, 3.37). Compared to residence within the university hostel and its environs, residing in town was associated with risk of testing positive for any drug: aRR 1.67 (95%CI 1.16, 2.42). Having one and multiple sexual partners were associated with risk of self-reported drug use: aRR of 1.55 (95% CI 1.05, 2.28) and 2.05 (95% CI 1.28, 3.27) respectively. While compared to residence in university hostel and its environs, residing in town was associated with risk of self-reported drug use: aRR 1.48 (95%CI 1.05, 2.08). Conclusion : Irrespective of the method used to record data alcohol, tobacco products (cotinine), marijuana and amphetamine or khat were the most preferred drugs. The usage was solely, concurrently or simultaneously. Future interventions should focus on continuing students, students’ residence and those who are sexually active. Key words : Self reported drug use; saliva analysis; poly-drug use; and university students