BACKGROUND: Unawareness of deficits after acquired brain injury (ABI) is often reported in the clinic. Several methods have been developed to measure a patient's awareness of deficits after ABI; however, no criterion standard currently exists to measure this phenomenon. OBJECTIVE: To review all instruments for measuring awareness of deficits and evaluate their psychometric and conceptual properties as well as their feasibility. METHODS: Systematic literature search for available awareness measurement instruments used in experimental ABI studies. Instruments were divided into the following 4 assessment methods: clinician ratings, structured interviews, performance-based discrepancy, and self-other rating discrepancy methods. The quality of the instruments was evaluated. RESULTS: The literature search identified 39 instruments and 8 of these were selected. The following 3 instruments stood out in terms of quality: Self-Awareness of Deficits Interview, Patient Competency Rating Scale, and Awareness Questionnaire. CONCLUSION: Although these quantitative instruments are useful tools in research, they have limited utility in the clinic because they only measure intellectual awareness. Therefore, in addition to these instruments, qualitative tools should also be used to gain a complete view of a patient's awareness problem. Copyright © 2012 Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited.