Abstract: Antifungal activity of aqueous extracts of locally available plants which are known for their medicinal values were tested in vitro against Drechslera oryzae, the causal organism of brown leaf spot of rice. The plants extracts were tested against the mycelial growth of D. oryzae at different concentrations of 5%, 10%, 15% and 20% using poisoned food technique. Among the plants extracts, Acorus calamus extract at 20% concentration alone showed 80.0% inhibition of mycelial growth whereas the other tested plants showed less inhibitory effect. In field trial, aqueous extract of Acorus calamus showed maximum percentage of disease control and reduced the disease incidence by 45.29% as compared with control plot.