Abstract The chemical composition of the essential oil of Mentha pulegium from Bulgaria has been determined by GC and GC/MS. The yields of oil obtained by water and steam distillation were 1.54% and 1.48%, respectively. The basic components, among the identified 21 were pulegone (42.9â45.4%), piperitenone (21.7â23.1%) and isomenthone (11.3â12.8%). There were no substantial qualitative differences between the oils obtained by water or steam distillation.