Deep neck space infections, which affect soft tissues and fascial compartments of the head and neck, were frequently encountered in the preantibiotic era, and their frequency has been remarkably reduced after the development of chemotherapeutic agents and antibiotics. But they may still result in significant morbidity and mortality despite the use of chemotherapeutic agents and antibiotics. A retrospective study was performed on 51 deep neck space infections in patients admitted for diagnosis and treatment at National Medical Center, during a 10-year period from March 1980 to February 1990. The following results were obtained ; 1) Age of the patient varied from 2 to 79-year-old and sex ratio of male to female was 1.1 : 1. 2) Sites of infection were submandibular space 25 cases(49.0%), lateral pharyngeal space 17 cases(33.3%), and retropharyngeal space 9 cases(17.6%). 3) Origins of infection were considered as acute pharyngotonsillitis 10 cases(19.6%), dental disease 9 cases(17.9%), diabetes mellitus 4 cases(7.8%), tuberculosis 3 cases(5.9%), recent tooth extraction 2 cases(3.9%), long standing steroid administration 1 case(2.0%) and unknown origin 21 cases(41.2%). 4) The isolated pathogenic organisms commonly involved were hemolytic streptococcus 9 cases(17.9%) and staphylococcus aureus 9 cases(17.9%). 5) All cases were treated with a) Conservative management only 19 cases(37.3%). b) Surgical drainage and antibiotics 24 cases(47.1%). c) Surgical drainage with tracheostomy and antibiotics 8 cases(15.7%). 6) Complications were airway obstruction 8 cases(15.7%), pneumonia 5 cases(9.8%), sepsis 2 cases(3.9%), mediastinitis 2 cases(3.9%), cutaneous fistula and skin necrosis 1 case(2.0%) and death due to bleeding 1 case(2.0%).