Variations in the essential oil composition of Thymus vulgaris L. cultivated in Estonia and in other European countries were determined using capillary gas chromatographic analysis methods. Fifty-nine components were identified, representing over 95% of the total oil yield. The principal components in the oils of common thyme were thymol (0.9%-75.7%), carvacrol (1.5%-83.5%), p-cymene (4.3%-34.4%), gamma-terpinene (0.9%19.7%), linalool (0.4%-4.8%), (E)-beta-caryophyllene (0.5%-9.3%) and terpinen-4-ol (tr.-3.8%). The sum of phenolic compounds (thymol and carvacrol) in the oils studied varied from 19.4% to 84.4%, and the sum of their precursors (p-cymene and gamma-terpinene) ranged from 5.7% to 38.5%. Thymol content was predominant in the oils of Holland (65.5%) and of Estonia (75.7%) but carvacrol content predominated in the Greek thyme oil (83.5%). Armenian thyme oil contained only 17.0% of thymol, but it was rich in neral and citronellol (32.5%), borneol (4.3%), citronellal (4.0%), 1,8-cineol (4.0%) and methyl eugenol and thymol acetate (7.5%). In Estonia, the thymol, thymol-carvacrol and thymol-p-cymene-gamma-terpinene chemotypes of the common thyme are distinguishable.