Nitrogen balance studies and clinical observations were made on two groups of patients suffering from obstructive carcinoma of the oesophagus. In 10 patients (group A) parenteral nutrition with a high calorie and nitrogen content was given pre- and early postoperatively. Five patients (group B) received intravenous dextrose/saline solution pre- and postoperatively with no nitrogen supply. Patients in group A had a positive nitrogen balance before and after operation and had a satisfactory postoperative progress. The patients in group B had a negative nitrogen balance until the resumption of oral feeding and their postoperative progress was not as satisfactory as that of patients in group A.