Abstract: Rice brown spot caused by Helminthosporium oryzae Breda de Hann is a major constraint for rice production. Fifteen seed extracts were evaluated at 10% concentration under laboratory condition against Helminthosporium oryzae. Among them rhizome extract of turmeric (Curcuma longa L.), seed extracts of sundavathal (Solanum indicum L.) and Vedpalai (Wrightia tinctoria Roxb.) exerted the maximum inhibition of the mycelial growth and spore germination of H. oryzae proving the antifungal activity against the pathogen. Thus the plant extract with mycotoxic effect can be well exploited in future for the control of H. oryzae in rice.