Phytopathogenic fungi are responsible for approximately 70% of cultivated plant diseases. These fungi, which are capable of infecting any tissue of the plant and at any stage of its growth, can cause both qualitative and quantitative damage. Currently, the main means of combating plant diseases are: Cultural struggle, genetic struggle, biological struggle, Physical struggle and Chemical struggle which are generally very specific to each group. These solutions are not effective in the long term and can lead to the appearance of new pathogenic races through mutations or random and spontaneous parasexualities in addition to environmental pollution as well as residues may be present in the water, the ground and also in the finished product. Hence the need to find alternative solutions to continue to fight against diseases by minimizing the different methods of control mentioned above and by reducing the use of chemicals. In addition, the innovation of biofungicides has become a necessity for the benefit of humans and the environment. Essential oils have a very broad spectrum of activity, mainly due to their nature. The aim of this work is to study the antifungal activity of the essential oil of cloves on three phytopathogenic fungi: Fusarium oxysporum, Rhizoctonia solani, Alternaria alternata. Clove essential oil showed strong antifungal activity against the fungi tested.