Fifty-nine spring and 7 winter barley varieties in lsquoThe Danish List of Varieties of Agricultural Crops, 1983/84rsquo were examined for variation at 39 isoenzyme and two hordein loci. Twenty-three isoenzyme loci had one allele only, and 16 loci had from two to five alleles. One hordein locus had 12 and the other 15 alleles. The variation in the 16 enzyme loci permitted the division of the 66 varieties into 63 groups, while the two hordein loci produced 34 groups. A study of 20 individuals from each variety showed that 22 varieties were polymorphic in at least one locus. Eight starch gel electrophoresis with various buffer systems, one agar gel electrophoresis (for amylases), and one polyacrylamide gel electrophoresis (for hordein) were performed to develop the patterns associated with the 41 loci. The polyacrylamide gel electrophoresis developing hordein patterns was clearly the most powerful single system for identifying barley varieties because of the large number of alleles.