Background: Descending necrotizing mediastinitis (DNM) is an acute, serious, septic disease which results from a complication of oropharyngeal infection. The disease requires a prompt diagnosis and radical surgical treatment to reduce high mortality (40%). The optimal form of mediastinal drainage remains controversial. The reason for publishing this report is both the fact that DNM is very rare and our experience preferring thoracotomy as an optimal approach to treating the disease. Case report. We reported a 34-years-old woman with DNM. The disease began as a peritonsillar abscess. After a bilateral double pleural drainage the disease worsened. In order to achieve radical mediastinal debridement and drainage, we carried out posterolateral right thoracotomy. We also had to perform left thoracotomy because of massive bleeding caused by septic erosion. There were no more reoperations. Conclusion. Aggressive surgical treatment, regardless the localization and the extent of changes is the key to success in the treatment of patients with necrotizing mediastinitis.