Long-term nitrogen balance periods over 17 and 24 days were performed in 5 healthy volunteers (2 females, 3 males) in order to evaluate the requirements under varying input of whole egg protein. Nitrogen balances are consquently influenced in a positive or negative way by increased or decreased protein intake. The estimation of protein requirements, an important precondition for evaluation of biological value of proteins and/or amino acid mixtures, however, is not influenced as far as experiments are conducted in the linear region between input and balance. In spite of considerable variations of protein intake maximum alterations of requirements of 20, and average ones of 10 per cent points are shown. Even under most unfavorable conditions of comparison potato egg pattern of amino acids administered orally and parenterally exceeds egg protein, given orally, at least by 7, atthe most by 27 points, and reported values of amino acids according to ROSE'S or to the plasma pattern by 36, 23, and 21 points.