Disclosed are major allergenic proteins in cashew nut, which are legumin-like proteins and 2S albumins. Also disclosed is a polypeptide allergen in the 7S superfamily, which includes vicilin-like and sucrose binding proteins. Several linear epitopes of the cashew nut are identified and characterized. The invention further discloses the sequence of cDNA encoding the allergenic polypeptide, the allergen being designated Ana o 1, and also describes the characterization of the expressed recombinant polypeptide and associated methods employing the polypeptide.