Purpose The purpose of this study was to evaluate the internal consistency and construct validity of the Traumatic Brain Injury Quality of Life Communication Item Bank (TBI-QOL COM) short form as a parent-proxy report measure. The TBI-QOL COM is a patient-reported outcome measure of functional communication originally developed as a self-report measure for adults with traumatic brain injury (TBI), but it may also be valid as a parent-proxy report measure for children who have sustained TBI. Method One hundred twenty-nine parent-proxy raters completed the TBI-QOL COM short form 6 months postinjury as a secondary aim of a multisite study of pediatric TBI outcomes. The respondents' children with TBI were between 8 and 18 years old ( M age = 13.2 years old) at the time of injury, and the proportion of TBI severity mirrored national trends (73% complicated-mild; 27% moderate or severe). Results The parent-proxy report version of the TBI-QOL COM displayed strong internal consistency (ordinal α = .93). It also displayed evidence of known-groups validity by virtue of more severe injuries associated with more abnormal scores. The instrument also showed evidence of convergent and discriminant validity by displaying a pattern of correlations with other constructs according to their conceptual relatedness to functional communication. Conclusions This preliminary psychometric investigation of the TBI-QOL COM supports the further development of a parent report version of the instrument. Future development of the TBI-QOL COM with this population may include expanding the content of the item bank and developing calibrations specifically for parent-proxy raters. Supplemental Material https://doi.org/10.23641/asha.7616534.