Objective: The purpose of this study was to examine the relation between white matter integrity of the brain, as measured by diffusion tensor imaging (DTI), and postconcussion symptom reporting following traumatic brain injury (TBI). Method: Participants were 34 U.S. service members (Age: M = 29.7 years, SD = 7.9, 97.1% male) who sustained a mild-moderate TBI; enrolled from Walter Reed National Military Medical Center. Participants completed the Neurobehavioral Symptom Inventory (NSI) and DTI, on average, 4.6 months post-injury (SD = 3.2). Participants were divided into groups based on DSM-IV symptom criteria for postconcussional disorder (PCD): (a) PCD-Present (n = 10) and (b) PCD-Absent (n = 24). A subgroup of 19 participants was also evaluated at 12 months post-injury (8 PCD-Present, 11 PCD-Absent). Results: There were significant differences (p < .05) and/or meaningful effect sizes (d>.50) for approximately half of the 18 regions of interest (ROI) when using measures of axial diffusivity (AD; d = .55–.95), mean diffusivity (MD; d = .52–1.03), and radial diffusivity (RD; d = .51–.75; PCD-Present > PCD-Absent). However, when considering all 18 ROIs simultaneously, there were no group differences (p > .05) for the mean number of ROIs that fell within normal limits for AD, MD, RD, and Fractional Anisotropy (p > .05). Longitudinal comparisons revealed no association between PCD and the number of DTI measures that fell within normal limits from baseline to 12 month follow-up. Conclusion: These results suggest that there may be some association between reduced white matter integrity in the brain and self-reported postconcussion symptoms within the first 12 months following mild-moderate TBI for some people. However, in this sample, this association was weak at best.