Purpose Opioids have long been a mainstay of treatment for pain in patients with orthopaedic injuries, but little is known about the accuracy of self-reported narcotic usage in orthopaedic trauma. The purpose of this study is to evaluate the accuracy of self-reported opioid usage in orthopaedic trauma patients. Methods A retrospective review of all new patients presenting to the orthopaedic trauma clinic of a level 1 trauma centre with a chief complaint of recent orthopaedic-related injury over a 2-year time frame was conducted. Participants were administered a survey inquiring about narcotic usage within the prior 3 months. Responses were cross-referenced against a query of a statewide prescription drug monitoring program system. Results The study comprised 241 participants; 206 (85.5%) were accurate reporters, while 35 (14.5%) were inaccurate reporters. Significantly increased accuracy was associated with hospital admission prior to clinic visit (beta = - 1.33; chi(2) = 10.68, P < 0.01; OR: 0.07, 95% CI 0.01-0.62). Decreased accuracy was associated with higher pre-visit total morphine equivalent dose (MED) (beta = 0.002; chi(2) = 11.30, P < 0.01), with accurate reporters having significantly lower pre-index visit MED levels compared to underreporters (89.2 +/- 208.7 mg vs. 249.6 +/- 509.3 mg; P = 0.04). An Emergency Department (ED) visit prior to the index visit significantly predicted underreporting (beta = 0.424; chi(2) = 4.28, P = 0.04; OR: 2.34, 95% CI 1.01-5.38). Conclusion This study suggests that most new patients presenting to an orthopaedic trauma clinic with acute injury will accurately report their narcotic usage within the preceding 3 months. Prior hospital admissions increased the likelihood of accurate reporting while higher MEDs or an ED visit prior to the initial visit increased the likelihood of underreporting.