In this study; screened five essential oils for fungitoxic effect against Penicillium digitatum that infect orange fruits. The five essential oils were commercial products derived from clove, thyme, sesame, black cumin and cinnamon. Antifungal activity of essential oils was compared by poisoned agar technique. In laboratory; among essential oils clove was the most effective showed 100% inhibition of mycelial growth at 1% concentration. Less antifungal effect was found with essential oils from cinnamon and thyme, while the oils from black cumin and sesame manifested no inhibition. Microscopic study on effect of essential oils on spores of P. digitatum showed distortion and shrinkage. Some essential oils might be promising source of a biological fungicide, applied directly before harvest or during postharvest.