The objective is to describe the characteristics of mechanically restrained patients in the emergency department (ED) of a university hospital and to evaluate the quality of restraint documentation that was filled out according to the dedicated protocol with respect to the law on restraint. All adult patients (≥16 years) who were admitted to the ED from January 2009 to December 2010 and were mechanically restrained were included. We assessed medical and demographic characteristics, the completeness of the dedicated protocol, and the concomitant use of chemical sedation. 72,844 patients were admitted to the ED. Of these, 593 (0.81%) were mechanically restrained. Two types of patients were restrained: young patients under the influence of psychoactive substances who were usually discharged home, and confused older patients who were hospitalized. 186 dedicated protocols were missing (31.4%). From the 407 filled-out protocols, only 119 (29.2%) were complete. Of the mechanically restrained patients, 215 (36.2%) received additional chemical sedation. Even though restraint is strictly regulated by law, many protocols justifying the privation of liberty were not filled out. This emphasizes the need for strict respect of the dedicated protocol and the use of guidelines and training sessions for nursing and medical staff that address specific procedures for the two categories of patients needing to be restrained.