Treatment results of 38 cases of septic mediastinitis for the last 17 years were analyzed. The frequency of mediastinitis as a complication of the penetrating wound was 0.28%, and of the closed thoracic trauma - 0.1%. Reasons and risk factors of the mediastinitis development have been revealed. The enlargement of the mediastinum on the X-ray allowed the primary diagnostics of suspicion on the mediastinitis in 39.5% of cases. The spiral computed tomography provided information for the further treatment options. The mediastinum drainage was an effective method of treatment, providing the improvement in 69.6% patients after penetrating wound and in 73.3% after the closed thoracic trauma.