Origanum dubium Boiss. is one of the economically important wild oregano species and it is intensely collected from the natural flora of Antalya in Turkey. Carvacrol chemotype of Origanum dubium is used mainly for essential oil production due to its high essential oil content. In this study, chemical diversity of Origanum dubium was investigated in order to develop new cultivars with improved essential oil yield and carvacrol content using clone selection method under cultivated condition. Essential oils obtained by hydrodistillation of the aerial parts of Origanum dubium were analysed by GC-MS and 24 different components were identified. In these genotypes, carvacrol was the major component and followed by p-cymene, gamma-terpinene, myrcene and alpha-thujene. Among the selected genotypes, essential oil yields were varied between 5.0% to 14.0%; carvacrol rates were varied between 73.76% to 88.21%; and p-cymene rates were varied between 3.16% to 9.10%.