Dental auxiliary is a term for all persons who assist the dentist in delivering dental care. They can be classified into operating or non-operating depending upon whether they are allowed to carry out any intraoral procedures in the treatment of the patients. The primary purpose of dentists delegating functions to allied dental personnel is to increase the capacity of the profession to provide patient care while retaining full responsibility for the quality of care. This chapter describes the duties and functions of the various auxiliary personnel. Highlighted here are the newer types of dental assistant by the California Dental Association 2006 (CDA) USA, the registered restorative assistant in extended functions, the auxiliarie’s personnel in India and the practice of four handed dentistry.