Biochemical analyses of seed storage proteins of Phaseolus coccineus have been carried out to identify seventeen different cultivars. The electrophoretic patterns in native polyacrylamide gel electrophoresis (PAGE) and denaturing conditions (SDS-PAGE); evidenced qualitative and quantitative differences for the three major protein components: legumin, vicilin and phytohaemagglutinin (PHA). The results were confirmed by isoelectrofocusing (IEF) analyses. Erythroagglutination tests showed the presence of high agglutinating activity particularly in cultivars with low vicilin content. The experimental results allow one to distinguish all the cultivars by their electrophoretic spectra and agglutinating activities.