This article analyzes 57 reports published in the years 1983 through 1964 that addressed the issue of the renal hemodynamic response to an oral protein load. Seventy-three groups are reported in those studies: 52 were healthy subjects (n = 627) and 21 had renal disease (n = 256); 47 were studied using inulin (n = 407 healthy people and 112 renal patients); 26 groups were studied using creatinine (n = 220 healthy people and 144 renal patients). Patients with liver cirrhosis were also analyzed. There was great heterogeneity in methodology used, emphasizing the need for standardization. The role of plasma amino acids, glucagon, insulin, growth hormone, PGE2, 6-ketoPGA1 alpha, brain-gut peptides, ANP, AVP, dopamine, and kinins in promoting the renal hemodynamic response to an oral protein load is discussed.