Objective: To examine convergent validity of the Brief Test of Adult Cognition by Telephone (BTACT) by determining correlation with established neuropsychological tests, administered an average of 4.4 days apart, in an inpatient traumatic brain injury (TBI) population. Setting: Acute inpatient rehabilitation hospital. Participants: Fifty-five patients receiving inpatient rehabilitation for new-onset TBI (69.1% male; mean age = 37 years, SD = 14 years). Design: Cross-sectional, secondary data analysis. Main Measures: BTACT; California Verbal Learning Test - second edition (CVLT-2); Wechsler Adult Intelligence Scale-IV (WAIS-IV) Digit Span; Trail Making Test; semantic fluency; phonemic fluency; Symbol Digit Modalities Test; Wisconsin Card Sorting Test. Results: The BTACT was significantly associated with established neuropsychological tests across composite scores of overall cognition (r = 0.64, P <.001), episodic verbal memory (r = 0.66, P <.001), and executive function (r = 0.56, P <.001). For BTACT subtests, Word List Immediate Recall and Word List Delayed Recall were correlated with CVLT-2 learning trials total score (r = 0.57, P <.01) and long delay free recall (r = 0.60, P <.001), respectively. BTACT Digits Backward correlated with WAIS-IV Digit Span (r = 0.51, P <.01). BTACT Animal Fluency was associated with semantic fluency (r = 0.65, P <.01), phonemic fluency (r = 0.60, P <.01), and Trail Making Test Part B (r = 0.39, P <.01). Conclusion: BTACT composite scores of overall cognition, verbal memory, and executive function demonstrate initial convergent validity in a TBI inpatient population. Future research should examine validity in a larger sample of individuals with TBI.