Background. Empyema thoracis is a common thoracic problem with a multitude of therapeutic options. The modified Eloesser flap (MEF) is one means of dealing with this problem in selected complicated patients. The purpose of this study is to report our 26-year experience with the MEF. Methods. A review of 78 patients who had a MEF from 1975 to 2001 was performed. Results. There were 52 males (67%) and 26 females (33%). Mean age was 59 ± 14 years. The overall length of stay was 26 ± 27 days, while mean postoperative length of stay was 16 ± 17 days. Microbiology of the empyema cavity revealed a predominance of gram-positive organisms. Before a modified Eloesser flap, all patients failed initial conservative interventions and 23 patients (29%) failed surgical interventions. Operative indications were as follows: parapneumonic effusions, 35 patients (45%); postresectional, 23 patients (29%); tuberculosis related, 7 patients (9%); malignant effusion, 4 patients (5%); esophageal fistulas, 4 patients (5%); abdominal sepsis, 3 patients (4%); and hemothorax secondary to trauma, 2 patients (3%). The inverted-U incision was performed in all patients. Average rib resection was 3 ± 1 ribs. There were no intraoperative complications and adequate drainage was achieved in all patients. Thirty-day morbidity/mortality was 4 patients (5%): 3 died of sepsis and 1 died of metabolic encephalopathy; although long-term follow-up (mean: 109 ± 141 months) revealed no additional morbidity related to the MEF. Conclusions. We demonstrate that MEF can be performed as a safe, definitive surgical procedure for the treatment of chronic empyema thoracis. The MEF remains an important option in the surgical treatment of chronic, complicated empyema thoracis.