Background. A relationship between tobacco or alcohol use and suicide risk has been identified, mainly in adult clinical samples; less is known of such interaction in non-clinical settings or school samples. Objective. To examine the association between tobacco or alcohol and suicide risk in a sample of freshman college students. Method. The Suicide Risk Inventory for Adolescents (IRISA) and the Alcohol, Smoking and Substance Involvement Screening Test (ASSIST) were used in a school-based screening program. Pearson coefficients and odds ratios were estimated for assessing degree of association. Results. Correlations were found between some areas of suicide risk and scores for alcohol use, but none with tobacco use. Nevertheless, suicide risk triples among consuetudinary smokers. Discussion. Both substances are associated with suicide risk in different forms; therefore their screening or assessment is suggested in preventive actions or early identification programs with college students.