Abstract: OBJECTIVE: Using a dyadic approach with military couples, the current study examined family risk factors for chronic neurobehavioral symptoms in service members and veterans (SMVs) following a mild traumatic brain injury (MTBI). SETTING: Military Treatment Facility. PARTICIPANTS: SMV ( n = 122) and intimate partner (IPs, n = 122) dyads ( N = 244). DESIGN: Prospective cohort. MAIN MEASURES: SMVs completed seven neurobehavioral outcome measures. Their intimate partners completed 12 health-related quality of life (HRQOL) risk factor measures. Both members of the dyad completed three family relationships risk factor measures. RESULTS: The number of neurobehavioral measures that were clinically elevated (≥60 T) were summed and used to classify SMVs into three outcome groups: (1) None/Few Symptoms [0-1 elevated scores]; (2) Several Symptoms [2-3 elevated scores]; and (3) Many Symptoms [4-7 elevated scores]. SMVs in the Many Symptoms group had significantly higher scores on nine family risk factor measures compared to the None/Few Symptoms group, and seven family risk factor measures compared to the Several Symptoms group. The Several Symptoms group had higher scores on one risk factor measure compared to the None/Few Symptoms group. The largest effect sizes were found for the SMV family relationships risk factor measures. SMVs were 4.2 to 13.0 times more likely to have poor neurobehavioral outcomes when they had negative versus positive family relationships. CONCLUSION: An important and unique addition to the literature was the finding that a range of risk factors in the SMV's family environment were strongly associated with clinically elevated chronic neurobehavioral symptoms following an MTBI. The establishment of the Family Wellness Program within the Defense Intrepid Network will open the door for family wellness to have a long-term place in military TBI treatment programs as a holistic, family-centered interdisciplinary model of care for warfighter brain health and return to duty following a TBI, and healthy, resilient, and military ready families.