Biological control of soil borne plant pathogens is a potential alternative to agrochemicals that are harmful to human health and for the environment. Antifungal potential of acetone extracts of four medicinal plants (Acorus calamus, Arctium lappa, Origanum vulgare and Thymus serpyllum) of different families were tested against Fusarium oxysporum f.sp. lycopersici causal agent of wilting in Tomato. Leaves of four medicinal plants were examined for antifungal activity in vitro using the Poisoned food technique. Among four plant species tested, acetone extract of Arctium lappa has recorded significant antifungal activity against the test fungi. Whereas, other plant extracts showed moderate to minimum antifungal activity. These findings suggests that some plant extracts tested possess antifungal activities against Fusarium oxysporum and could be used as potential antifungal agents for the control of fungal plant diseases.