The cataloguing of wheat (Triticum aestivum L.) cultivar isozyme patterns, though a routine exercise, provides useful data for genetic and breeding studies. Isozymes of five kernel enzyme systems (β-amylase, esterases, malate dehydrogenase, superoxide dismutase, and glucose phosphate isomerase) were separated by isoelectric fosusing (IEF) for 80 North American winter wheat cultivars. No variation in malate dehydrogenase, superoxide dismutase, or glucose phosphate isomerase IEF patterns was detected. There were three groups of hard red winter wheat cultivars with esterase patterns that differed from the pattern common to all others: Arkan and Sage; Siouxland, Colt, and Pioneer 2157; and Sandy. Esterase IEF, in contrast to gliadin electrophoresis in other studies, distinguished Sage from Eagle and Larned. Four soft red winter cultivars (Compton and Adena; Florida 302; Roland) and six groups containing a total of eight hard red winter cultivars (RHS812; RHS830; Norstar; Plainsman V; TAM 105, TAM 107, and Rose; and TAM 101) had variant β-amylase patterns. Some of the esterase and β-amylase varients, produced by genes on chromosomes 3A, 3D, 4D, 5A, and possibly others, may be useful in linkage studies.Key words: Cultivar identification, electrophoresis, β-amylase, esterase, superoxide dismutase, glucose phosphate isomerase