The Validity of the Montreal Cognitive Assessment for Moderate to Severe Traumatic Brain Injury Patients: A Pilot Study Objective To pilot the use of Montreal Cognitive Assessment (MOCA) as a quick clinical screen for cognitive assessment in traumatic brain injury (TBI) patients. Design The study recruited 61 participants with moderate to severe TBI presenting to a tertiary rehabilitation center under the Brain Injury Program. A MOCA questionnaire and neuropsychological battery (Repeatable Battery for the Assessment of Neuropsychological Status [RBANS] and Color Trails Test[CTT]) were administered to participants who had completed inpatient rehabilitation. Results Receiver Operating Characteristic (ROC) analysis for the MOCA revealed an optimal balance of sensitivity and specificity at 24/25 to discriminate participants who were classified as less than 5th centile on the Total Scale Index on the RBANS. This achieved a sensitivity, specificity, PPV and NPV of 73.9%, 86.5%, 77.3% and 84.2% respectively. ROC analysis for the trail making subtest of the MOCA achieved a sensitivity, specificity, PPV and NPV of 79.4%, 74.1%, 79.4% and 74.1% in identifying patients classified as less than 5th centile on CTT Part 2. Conclusion The use of MOCA displayed good validity in identifying patients with clinically significant impairment on a standard neuropsychological assessment battery in the study population. However, it may lack sensitivity for estimating mild levels of impairment. All correspondence and requests for reprints should be addressed to: Matthew Rong Jie Tay, Tan Tock Seng Hospital Rehabilitation Center, c/o TTSH Rehabilitation Center @ Ang Mo Kio-Thye Hua Kwan (AMK-THK), 17, Ang Mo Kio Ave 9, Singapore 569766, Republic of Singapore. The authors confirmed that with regard to this submitted article, we have none of the following disclosures: competing interests, funding or grants or equipment from any source, and financial benefits to the authors, nor have we previously published any part or whole of this original work. Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.