The objective of the present study was to present a new complaint questionnaire designed to assess a wide range of difficulties commonly reported by patients with acquired brain injury.Patients (n 5 619) had been referred to a community re-entry service at a chronic stage after brain injury, mainly traumatic brain injury (TBI). The Brain Injury Complaint Questionnaire (BICoQ) includes 25 questions in the following domains: cognition, behavior, fatigue and sleep, mood, and somatic problems. A self and a proxy questionnaire were given. An additional question was given to the relative, about the patient's awareness of his difficulties. The questionnaires had a good internal coherence, as measured with Cronbach's alpha. The most frequent complaints were, in decreasing order, mental slowness, memory troubles, fatigue, concentration difficulties, anxiety, and dual tasking problems. Principal component analysis with varimax rotation yielded six underlying factors explaining 50.5% of total variance: somatic concerns, cognition, and lack of drive, lack of control, psycholinguistic disorders, mood, and mental fatigue/slowness. About 52% of patients reported fewer complaints than their proxy, suggesting lack of awareness. The total complaint scores were not significantly correlated with any injury severity measure, but were significantly correlated with disability and poorer quality of life (Note: only factor 2 [cognition/lack of drive] was significantly related to disability.) The BICoQ is a simple scale that can be used in addition to traditional clinical and cognitive assessment measures, and to assess awareness of everyday life problems.