AIM: Psychotropic drugs like opioids and benzodiazepines are prescribed for traumas resulting from road traffic crashes and the risk of developing an addiction deserves consideration. This study aims to shed light on how the consumption of those drugs evolves over time among older road traffic injury (RTI) victims. METHODS: We conducted a nationwide Swedish register-based longitudinal study to identify trajectories of post-RTI psychotropic drug use. All individuals aged 50 years and older who had a hospital visit for an RTI from 2007 to 2015 were followed up during a two-year period; those who used the drugs prior to the RTI were excluded. Trajectories were identified by performing latent class trajectory analysis on drug dispensation data for opioids and benzodiazepines separately (66,034 and 66,859 adults, respectively, in total). RESULTS: Three trajectories were identified for opioids and four for benzodiazepines. The largest group in both instances included people with no-use/minimal use throughout the follow-up (81.3% and 92.8%). "Sporadic users" were more frequent among users of opioids (16.7%) than benzodiazepines (4.3%), whereas "chronic users" were found in similar proportions (2.0% and 1.8%). "Delayed chronic use" characterized the fourth group of benzodiazepine users (1.0%). CONCLUSION: Several trajectories of psychotropic drug use were identified after RTI, from limited to chronic. Although chronic use was uncommon, a better understanding of the factors likely to increase that risk is warranted given the seriousness of the problem.< Réduire