Abstract Cognitive dysfunction is commonly reported but variable in course and severity in the primary brain tumor (PBT) population. Brief, reliable, and sensitive measures of patient-reported outcomes (PRO) of cognitive symptoms on function are needed for clinical care and research. This study aims to assess the reliability and validity of the Neuro-QoL Perceived Cognitive Function tool (NQC) and explore associations with symptoms and objective testing of cognitive dysfunction in a cohort of PBT patients enrolled in a natural history study (NCT02851706: PI T. Armstrong). Patient sample characteristics and PROs, including NQC (<40 = moderate/severe (MS) dysfunction), a symptom burden measure (MD Anderson Symptom Inventory-Brain Tumor (MDASI-BT), scores ≥5 = MS) and the Montreal Cognitive Assessment ((MoCA), scores ≤ 25 indicating cognitive impairment (range: 0-30)) were collected. Descriptive statistics and a psychometric analysis consisting of bivariate correlations, Cronbach’s alpha, and factor analyses using principal axis factoring with nonorthogonal rotation were performed. Cohen’s kappa and correlation were used to assess agreement between objective and subjective measures of cognitive function. The cohort included 327 patients who completed the NQC at study entry [median age: 47 years (range: 18-85), primarily white (78%) males (55%) with high-grade tumors (73%), 65% with a Karnofsky Performance Status (KPS) ≥ 90 (good), and 29% reporting MS cognitive dysfunction]. Factor analysis of the NQC identified two underlying factor groupings: concentration/focus and executive function with Cronbach’s alphas of 0.92 and 0.91 that are interpretable and provided adequate fit for the data. While the NQC was moderately correlated with several MDASI-BT symptom factors, it was highly associated with the cognitive factor (r = -.646). To assess agreement, a subset of patients also completed the MoCA (n=172). These were primarily male (58%), white (79%), had high-grade tumors (67%), and a good KPS score (67%). In this subset, 24% had MS cognitive dysfunction as measured by the NQC while 44% were cognitively impaired using the MoCA resulting in a kappa agreement of 0.07. The correlation between the MoCA score and NQC T-score was -0.292. Understanding the impact and prevalence of cognitive symptoms, objective cognitive testing, and perceived impact is essential for PBT patient care and identifying supportive care interventions. Select NQC psychometric properties demonstrate reliability and validity in this population, with strong agreement with self-report of cognitive symptoms but weaker correlation with objective testing, highlighting the variability in perceived impact. Future research in cognitive function will explore the use of objective testing and perceived impact, its predictors in select populations (i.e., IDH-mutant tumors), and examine its association with biomarkers. Citation Format: Morgan L. Johnson, Elizabeth Vera, Kimberly Reinhart, Hope Miller, Anna Choi, Tricia Kunst, Bennett McIver, Ewa Grajkowska, Michelle L. Wright, Terri S. Armstrong, Tito Mendoza. Psychometric analysis of Neuro-QoL Perceived Cognitive Function tool in primary brain tumor patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 7453.