Candidal mediastinitis is rare. We report nine cases encountered at our institutions since 1985; seven cases were diagnosed since 1993. All cases followed thoracic surgery, with a median time from surgery to disease onset of 11 days (range, 6-100 days). All patients received prior antibiotic therapy. Common clinical manifestations were chest wall erythema in 4 cases (44%), drainage in 5 (56%), fever in 4 (44%), and sternal instability in 4 (44%). Failure to obtain appropriate intraoperative specimens for cultures and the dismissal of cultures positive for Candida as contaminants delayed diagnosis in three cases (33%). Mediastinitis was complicated by contiguous or hematogenous spread in seven cases (78%); five patients (56%) had two or more complications. The mortality rate was 56%. Optimal therapy remains undefined, but on the basis of our experience, aggressive surgical debridement combined with antifungal therapy for at least 6 weeks is recommended. Prompt recognition and institution of therapy appear to be the keys to improving prognosis.