The suitable conditions established for the preparation of mung bean protein isolate (MI-I) were extraction at pH 9 and 25°C for 20 min using a 1:15 mung bean flour to solvent ratio, followed by precipitation at pH 4. MI-I had aboCt 92% protein (dry basis) and a high amount of lysine but was limiting in methionine and cystine. It had a cream color and very high solubility at pH above and below the isoelectric point. When added as a protein supplement to wheat flour, MI-I resulted in decreased dough and bread quality which can partly be offset by addition of sodium stearoyl-2-lactylate. Breads with MI-I at 10% level were acceptable and had 41% higher protein content and 73% higher PER than the unsupplemented bread. MI-l is comparable to a commercially available soy protein isolate and shows promise as a nutritional and functional ingredient in many food products.