Descending necrotising mediastinitis is one of the most lethal and least frequent forms of mediastinitis. It is a life-threatening infection most frequently originating from an oropharyngeal or odontogenic infection. A retrospective study of 6 patients diagnosed and treated for descending necrotising mediastinitis between 2015 and 2020 is reported. All patients were male, mean age of 34.83 years; 66% were smokers. 83% had an orocervical infection and 34% had initial mediastinal spread. All patients were treated initially with empirical broad-spectrum antibiotics and surgical drainage, with subsequent admission to the Intensive Care Unit; only one of them required tracheostomy. The mean hospital stay was 27.37 days. After a mean follow-up of 6 months, 100% of the cases had a complete recovery. Early diagnosis and surgical treatment combined with improved life-support treatment in intensive care units and broad-spectrum antibiotic therapy leads to a decrease in associated mortality.