This study validated the Brief Inventory of Psychosocial Functioning (B-IPF), an abridged version of the 80-item Inventory of Psychosocial Functioning (IPF; Bovin et al., 2018). The B-IPF-a 7-item self-report questionnaire that assesses posttraumatic stress disorder (PTSD)-related psychosocial functional impairment-was developed for use in settings in which the full IPF would be too time intensive to administer. In this study, we examined the psychometric properties of the B-IPF among a sample of 362 veterans recruited from 2 Veterans Affairs hospitals. The B-IPF demonstrated high internal consistency (Cronbach's alpha = .84) and adequate test-retest reliability (r = .65, p < .001). The B-IPF was strongly correlated with the IPF (r = .71, p < .01) and had higher correlations with measures of mental health impairment and quality of life (all rs > ∥.50∥; all ps < .001) than with a measure of physical health impairment (i.e., the Physical Component Summary; r = -.34; p < .001), which demonstrated strong construct validity. In addition, the B-IPF displayed strong criterion-related validity, with higher correlations with a PTSD symptom measure, (r = .63, p < .05), and measures of other internalizing disorders (all rs > .44; all ps < .05) and a lower correlation with a measure of an externalizing disorder (r = .14; p < .05). These results indicate that the B-IPF is a reliable and valid instrument for assessing PTSD-related impairment. The strong psychometric properties of the instrument, in addition to its length, make it ideal for settings in which time is a factor. (PsycInfo Database Record (c) 2020 APA, all rights reserved).