Many initiatives have been proposed to improve emergency department (ED) overcrowding. One such strategy has been to implement medical assessment units (MAUs). This study reports on an environmental scan of MAU distribution and characteristics across Canada. A telephone survey was administered to administrative and clinical leaders at acute-care hospitals in Canada. The survey was designed in two sections: (1) description of hospital and ED characteristics; and (2) description of any existing MAU-like units associated with the hospital's ED structure and processes. Our survey reveals that MAU-like initiatives exist in several Canadian hospitals but are heterogeneous in structure and functionality.