Brain injury often results in cognitive impairments and neurobehavioral deficits that effect recovery, rehabilitation, and general adjustment. Aggressive behaviors and agitation, well-known consequences of cerebral damage, are the most difficult for caregivers to evaluate and manage and the most stressful for patients and families. This study was designed to determine the efficacy of an observational protocol (Cognitive Behavioral Rating Scale, CBRS) in evaluating cognition and its usefulness with demographic, medical, and psychological information in predicting aggressive behaviors of cerebrally damaged patients. Twenty-eight brain-injured patients consecutively admitted to a brain injury unit were evaluated by nurses who used the CBRS after first establishing interrater reliability in using the instrument. Relationships were determined between results of the CBRS, demographic information, medical and psychological information; the variable in each category that was most highly correlated with aggressive behaviors was then used in a multiple linear regression to predict the frequency of aggressive behaviors. Discussion focused on disorientation to place and time as the most significant predictors of aggressive behaviors, as well as the prescriptive use of antiseizure medications and the number of medical comorbidities.