It is difficult to fully assess an agitated patient, and the complete psychiatric evaluation usually cannot be completed until the patient is calm enough to participate in a psychiatric interview. Nonetheless, emergency clinicians must perform an initial mental status screening to begin this process as soon as the agitated patient presents to an emergency setting. For this reason, the psychiatric evaluation of the agitated patient can be thought of as a 2-step process. First, a brief evaluation must be aimed at determining the most likely cause of agitation, so as to guide preliminary interventions to calm the patient. Once the patient is calmed, more extensive psychiatric assessment can be completed. The goal of the emergency assessment of the psychiatric patient is not necessarily to obtain a definitive diagnosis. Rather, ascertaining a differential diagnosis, determining safety, and developing an appropriate treatment and disposition plan are the goals of the assessment. This article will summarize what components of the psychiatric assessment can and should be done at the time the agitated patient presents to the emergency setting. The complete psychiatric evaluation of the patient whose agitation has been treated successfully is beyond the scope of this article and Project BETA (Best practices in Evaluation and Treatment of Agitation), but will be outlined briefly to give the reader an understanding of what a full psychiatric assessment would entail. Other issues related to the assessment of the agitated patient in the emergency setting will also be discussed.