The misuse of benzodiazepines and opioid medications is frequent in students. To improve our understanding of this behavior, we aimed to identify factors associated with separate and concomitant use of these substances. Anonymous self-reported questionnaires were e-mailed to students enrolled at a French university between March and July 2021, covering: sociodemographic characteristics, academics, psychoactive substance use, ADHD symptomatology (adulthood and childhood), and psychiatric/psychological or addiction follow-up. Factors associated with the use of benzodiazepines and opioid medications included female sex (OR = 1.41 [1.08; 1.86]) and OR = 1.38 [1.06; 1.79], respectively), older age (OR = 1.65 [1.04; 2.6] and OR = 2.17 [1.4; 3.36], respectively), current psychiatric/psychological follow-up (OR = 6.53 [5.18; 8.24] and OR= 1.5 [1.12; 2.0], respectively), ADHD symptomatology (OR= 2.33 [1.71;3.16] and OR= 1.61 [1.15; 2.24], respectively), polyconsumption (tobacco use for benzodiazepine users, OR = 1.38 [1.04; 1.82]; alcohol use OR = 1.67 [1.17; 2.39] and tobacco use OR = 1.62 [1.23; 2.14] for opioid users). These factors were even more strongly associated with the concomitant use of benzodiazepines and opioid medications: older age (OR = 3.64 [2.22; 5.99]), female sex (OR = 1.54 [1.1; 2.14]), grade repetition (OR = 1.7 [1.14; 2.54]), psychiatric/psychological follow-up (OR = 4.51 [3.35;6.06]), ADHD symptomatology (OR = 5.3 [3.69; 7.63]), polyconsumption (tobacco use OR = 2.05 [1.39; 3] and cannabis use, OR = 2.07 [1.97; 4.16]. The factors associated with the use of benzodiazepines and prescription opioids identified in this study could lead to the development of targeted prevention methods.