Phytochemical analysis of the essential oils of Micromeria graeca (L.) Rchb from Vis and Komiza on the island of Vis (Croatia) showed them to have a similar chemical composition. The oxygenated sesquiterpene alpha-bisabolol was a major component of both oils with percentages of 13.9% in the oil from Vis and 15.5% in the oil from Komiza. A comparison of the mean number of lesions on the essential oil-treated Chenopodium quinoa plants infected with satellite-associated cucumber mosaic virus (satCMV) with the corresponding control showed that the oil from Vis caused delay in the development and reduction of the number of lesions by 59.3%. The essential oil of M. graeca from Komiza was not effective in the reduction of satCMV infection.