The objective of this study was to examine the prevalence of long-term psychiatric, neurologic, and psychosocial morbidities of self-reported mild traumatic brain injury (MTBI). A cross-sectional cohort sample of three groups was examined: those who had not been injured in a motor vehicle accident nor had a MTBI (n = 3,214); those who had been injured in an accident but did not have a MTBI (n = 539); and those who had a MTBI with altered consciousness (n = 254). Logistic regression analyses were used to model odds ratios for the association between group and outcome variables while controlling demographic characteristics, comorbid medical conditions, and early-life psychiatric problems. Compared with uninjured controls, MTBI increased the likelihood of depression and postconcussion syndrome. MTBI also was associated with peripheral visual imperceptions and impaired tandem gait. Similarly, the MTBI group had poorer psychosocial outcomes including an increased likelihood of self-reported disability, underemployment, low income, and marital problems. Results suggest that MTBI can have adverse long-term psychiatric, neurologic, and psychosocial morbidities.