Descending mediastinal infection (DMI) is rare and serious infection with a high mortality rate, which complicates from pharyngeal, odontogenic infection or esophageal perforation. Early recognition and treatment are essential in order to minimize morbidity and mortality. Evaluation with imaging diagnosis, especially with computed tomography is necessary to confirm the diagnosis and to facilitate surgical planning. The most important CT findings in diagnosis of DMI are widened mediastinum, air-fluid level in mediastinum and neck subcutaneous crackling. Estrera's criteria could be implementing for diagnosis of DMls. the authors present one series of 17 petients with diagnosis of DMI. From this study, the authors found that the pathology of DMls in Vietnam is commonly caused by esophageal perforation and the authors recommend performing the fibrogastroendoscopy associated with CT-scan for purposes of both diagnosis and intervention.