Abstract The neurobehavioral disability recognized in traumatic brain injury (TBI) is a severe sequela, but there is no appropriate classification due to its various manifestations. In the present study a questionnaire for a simple investigation of this disability was prepared, and its reliability and validity verified. The survey was conducted on 72 patients with TBI by the caregiver of each patient. As a result, good reliability was indicated by the split-half method (coefficient of reliability: 0.95, obtained using Spearman–Brown correction formula). The total score of the questionnaire had a significant correlation with the total score of the simultaneously conducted Japanese version of Neuropsychiatry Inventory at the 0.01 level (Spearman's rank correlation, 0.47). It also had a significant correlation with the total score of the simultaneously conducted Japanese version of the Dysexecutive Questionnaire at the 0.05 level (Spearman's rank correlation, 0.36). Six factors constituting this neurobehavioral disability were extracted from a factor analysis of the questionnaire survey. These factors are angry outburst, avolition, deficits of sympathy, depressed mood, discourse deficits, and degradation of appearance. Each factor indicated good internal consistency (Cronbach α, 0.86–0.94). The present results indicate that this questionnaire has good reliability and validity, therefore it can be a significant indicator in TBI neurobehavioral disability study.