Nitrogen balance studies in chronic severe uremia have shown that it is possible to convert the negative nitrogen balance on a protein-poor diet to a positive one when the diet is supplemented with the essential amino acids intravenously or orally. It has been possible to make the diet variable and good tasting. This is a great advance as the patients can remain on the diet for a long time. 15N-studies have shown that this nitrogen balance represents true protein synthesis. These studies have also shown that histidine may be an essential amino acid in chronic severe uremia and further improves the nitrogen balance. During long-term treatment with the diet supplemented with essential amino acids including histidine, no signs of progressive neuropathy, bleeding or muscle wasting have been observed. We think that this diet and amino acid regimen is a feasible way to keep chronic severe uremic patients in fairly good general condition and nutritive state until they can have a renal transplantation or a place in a home-dialysis program.