Polymorphism of ten enzymes, acid phosphatase (APH), isocitrate dehydrogenase (IDH), leucine aminopeptidase (LAP), phosphorylase (PP), superoxide dismutase (SOD), malic enzyme (ME), glutamate oxaloacetate transaminase 1 and 2 (GOT-1, GOT-2) and phosphoglucomutase 1 and 2 (PGM-1 and PGM-2), was investigated in three gene pools of cultivated chicory, including six cultivated wild chicory, eight industrial chicory and eight Brussels chicory varieties. LAP, APH, PP and PGM-2 showed high phenotypic polymorphism whilst GOT-1 and ME had poor polymorphism. For three enzyme coding loci Lap, Pgm-1 and Got-2, allele frequencies were determined. Isozyme composition in the three chicory gene pools was significantly different, showing, respectively, high, intermediate and poor average amount of phenotypic polymorphism in cultivated wild chicory, industrial chicory and Brussels chicory. Isozyme Variation within and between varieties of the three gene pools is discussed in relation to breeding practices.