In 212 patients with tumors in the head and neck region the nutritional status prior to, during, and following radiotherapy, was determined by body measurements and biochemical and immunological parameters. In 165 orally fed patients the nutritional parameters deteriorated rapidly under radiation and afterwards recovered only slowly and incompletely, 31 patients requiring PEG during radiotherapy. By contrast, 47 patients with a poor initial status who had a prospectively performed percutaneous endoscopically guided gastrostomy (PEG) experienced an amelioration of their nutritional status even before radiotherapy ended. The subjective status of the patients was assessed using the Padilla quality of life index. Here, too, the PEG patients had significantly worse initial values than the orally fed patients. As with the objective indicators of nutritional status a significant deterioration was seen in the orally fed patients during radiotherapy, while the scores of the PEG patients remained constant. We consider early institution of a carefully monitored enteral feeding by PEG useful for stabilizing the nutritional status of patients with tumors in the head and neck region, and therefore recommend, when aggressive multimodal therapy is planned-and particularly if primary malnutrition is already obvious-prophylactic performance of PEG prior to the start of therapy.