Please use this link to access publication Abstract Background Tetrahydrocannabinol (THC) can alter the coagulation cascade resulting in hypercoagulability. The aim of our study is to evaluate the impact of THC use on thromboembolic complications (TEC) in geriatric trauma patients (GTP). Methods This is a 2017 analysis of the TQIP database including all GTP (age ≥65 years). Patients were stratified based on THC use. Propensity score matching (1:2 ratio) was performed. Results A total of 2,835 patients were matched (THC+: 945 and THC-: 1,890). Mean age was 70 ± 6 years, 94% sustained blunt injuries, and median ISS was 22[12–27]. Sixty-two percent of patients received thromboprophylaxis, with median time to initiation of 27 h from admission. Overall, the...