Objective: The Texas Postconcussion Symptom Inventory (TPSI) is a novel, 66-item, self-report instrument with empirically-derived indices that provides a summed total score to assess recovery following concussion. This study evaluated convergent validity of the TPSI with the Sport Concussion Assessment Tool Post-Concussion Symptom Scale (PCSS), and examined differences in symptom scores between recovered and non-recovered adults to assess its utility in measuring post-concussion symptoms. Method: Adults (N=37; Mage=41.6; Female=59.5%; White=89.2%) diagnosed with concussion were recruited from a larger concussion study (ConTex) to complete the TPSI and PCSS three months after initial clinical evaluation. Convergent validity was assessed using nonparametric correlation analyses between total symptom severity scores on the PCSS and TPSI for all subjects. Independent sample t-tests examined whether the TPSI total symptom score differed between the adults reporting lingering symptoms (N=19) and those who had recovered (N=18). Results: Total TPSI symptom score strongly correlated with the PCSS total symptom score (ρ = .867; p<.001). Non-recovered adults (MTPSI = 55.61; SDTPSI = 26.38) reported significantly higher symptom scores than recovered adults (MTPSI = 34.64; SDTPSI = 22.69) on the TPSI t(35) = 2.59, p = .014, d = 0.85, 95% CI, [4.53, 37.32]. Conclusion(s): The TPSI demonstrated strong convergent validity with a common clinical postconcussion symptom instrument and identified significant differences in symptom reporting between recovered and non-recovered adults after a concussion. Future research will build upon these preliminary results and determine the utility of the TPSI in the acute stage following concussion as well as in tracking recovery.