A case of pio-pneumothorax complicating a splenic flexure colonic carcinoma is herein presented. The patient was a 58 years old male and was submitted 3 months earlier to a colo-colic bypass for a locally advanced tumor infiltrating stomach, spleen, tail of the pancreas and left emidiaphragm. Few days before the admittance in our ward, he experienced fever, anorexia, and severe dispnoea. Treatment was a water seal drainage of the chest evacuating nearly 8 Liters of purulent material where Escherichia coli was found. Death occurred 2 weeks after drainage. From the analysis of the literature thoracic empyema is an extremely rare complication of colonic carcinoma: 5 other cases have been reported so far. Pathogenesis in half of the cases was due to septicemia and in the others to infectious local spreading.