The purpose of this study was to examine the influence of the “good-old-days” bias on symptom reporting following mild traumatic brain injury (MTBI). The MTBI sample consisted of 86 patients (51.2% men) referred to a hospital-based concussion clinic in Vancouver, Canada. The majority of patients (83.7%) were evaluated within 3 months following their injury (M = 1.8 months, SD = 1.7, range = 0.2-8.0 months). Patients provided retrospective preinjury symptom ratings on the British Columbia Post-Concussion Symptom Inventory (BC-PSI). Ratings were compared with 177 healthy controls recruited from the community and a local university. MTBI retrospective ratings were significantly lower than the control group on the BC-PSI total score (p < .01, d = 0.27, small effect size) and 6 of the 13 individual items (all p < .05, d = 0.23-0.36, small to small-medium effect sizes). Patients who were currently in litigation reported more post-injury symptoms (p = .009, d = 0.63, medium-large effect size). However, litigation status was not associated with self-reported preinjury retrospective symptom ratings. Consistent with the "good-old-days" bias, patients with MTBI appear to misperceive their preinjury functioning as better than the average person.