We have reported previously that sensitivity to foods played an important role in six children with frequently relapsing steroid sensitive minimal change nephrotic syndrome (Lancet, in press). These investigations have been extended to include 4 more children with the same disorder and to 2 children, a 15-yr-old WM and 13-yr-old WF with membranous glomerulopathy and the nephrotic syndrome. The latter two patients had not received prednisone. Evaluation of use of food extract injections for diagnostic testing and therapy also was performed. All patients, off prednisone, were admitted to the Clinical Research Center for study. All patients showed decrease in 24 hr. protein excretion on restricted diets, exacerbation of proteinuria with ingestion of specific foods and decreased proteinuria with return to the previous limited diet. Oral challenge with milk produced alteration of plasma C3 in 6 of 7 patients. Serial measurements of serum proteins and immunoglobulins were also made. Two patients were again given milk and after onset of proteinuria, were tested intradermally with serial dilutions of milk extract. A treatment dose was determined and given daily s.q. while ingestion of milk continued. This produced rapid decrease in proteinuria toward normal amounts. Subsequently these patients and 3 previous patients have been treated with food extract injection therapy with improved control of their nephrosis.