Objective: To evaluate the reliability and utility of a brief quantitative measure of cognitive recovery, the Cognitive Log (Cog-Log), developed for daily use with rehabilitation inpatients to provide information about the recovery of higher neurocognitive processes including verbal recall, attention, working memory, motor sequencing, and response inhibition. Design: Descriptive study of the Cog-Log's normative scores, reliability (interrater, internal consistency), and validity as shown by its relationship to standard neuropsychologic measures. Setting: Inpatient rehabilitation hospital affiliated with a large university medical center. Participants: One hundred fifty neurorehabilitation inpatients with acquired brain injury; 83 young adults without acquired brain injury were included to provide normative data. Interventions: Not applicable. Main Outcome Measures: The Cog-Log; standardized neuropsychologic measures of memory (Wechsler Memory Scale-Revised, Rey Auditory Verbal Learning Test), language, attention (Wechsler Adult Intelligence Scale-Revised), and reasoning (Trail Making Test). Results: Reliability analysis showed strong interrater reliability across items (Spearman r, .749-1.00) and high internal consistency (Cronbach α=.778). Factor analysis of the CogLog using principal components extraction revealed a unitary factor (eigenvalue=3.48). Cog-Log items designed to measure working memory and immediate and delayed verbal memory were most strongly predictive of performance on similar standardized neuropsychologic measures administered on the same day. Conclusion: The Cog-Log appears to be a reliable and efficient tool for measuring ongoing neurocognitive recovery during inpatient rehabilitation. © 2003 by the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation.