Abstract: Antifungal activities of the essential oils obtained from oregano (Origanum syriacum var. bevanii), fennel (Foeniculum vulgare), Artemisia (Artemisia annua), laurel (Laurus nobilis) and lavender (Lavandula stoechas subsp. stoechas), growing in the Eastern Mediterranean Region of Turkey, were investigated against Penicillium digitatum, causal agent of green mould rot of citrus. Different concentrations of the essential oils on conidial germination and germ tube elongation were determined in vitro. The results indicate that essential oils of O. syriacum and F. vulgare were strongly inhibitory to conidial germination of P. digitatum compare with other essential oils used. Complete inhibition of conidia by essential oils of Origanum and Foeniculum was observed at concentrations of 64 and 352 μg mL-1, respectively. Essential oils of Lavandula, Artemisa and Laurus, however, failed to inhibit conidial germination completely at all concentrations used (32 to 352 μg mL-1). All essential oils were found to inhibit the germ tube elongation in a dose-dependent manner. Similarly, Origanum and Foeniculum oils, at 64 and 352 μg mL-1 concentrations, were found to inhibit the germ tube elongation completely. Essential oils of Lavandula, Laurus and Artemisia, at the highest concentration used (352 μg mL-1), reduced the germ tube elongation by 69, 58 and 28%, respectively. Microscopical observations revealed that both Origanum and Foeniculum oils significantly altered the morphology of P. digitatum hyphae.