Protein fromApios americana (termed Apios) seeds, a neglected NorthAmerican legume, was extracted using ultrafiltration and protein micellar mass methodologies. The goal was to enhance the utilization of A. americana seeds as a food ingredient in food systems. The protein content increased from23.4%(seed flour) to 74.1%(seed isolate).Amino acid composition of the extract was determined using ion-exchange column chromatography. The amino acid levels increased and the most abundant amino acids in the protein isolate were glutamic and aspartic acids. Leucine was the most predominant essential amino acid. Other essential amino acids present in higher amounts were phenylalanine, valine, threonine and lysine in descending order of abundance.