abstract seedlings obtained from seeds of three populations of oregano (origanum ehrenbergii) harvested in lebanon and sown at a research station in france were planted in three replicates in a fischer block design. oils produced by water distillation were subjected to analysis by gc and gc/ms. the oils of one of the populations were uniform and carvacrol-rich. the other population displayed a variable chemical composition, including thymol, thymol-carvacrol and p-cymene/-terpinene chemotypes.