Blast caused by Pyricularia grisea Sacc. is one of the major diseases of rice. In situations of sudden occurrence of the disease, use of fungicides is the only effective solution for the immediate suppression of the disease. An attempt was made to test the efficacy of Isoprothiolane (Fuji-One 40E) for the control of blast. Three doses of the fungicide, isoprothiolane (Fuji-One 40 E) was tested in comparison with the standard check fungicide Tricyclazole (Beam 75WP). All the three doses of the fungicide tested were statistically on par with the check fungicide, tricyclazole in reducing the disease and increasing the yield. Hence the lowest dose of isoprothiolane (Fuji One 40E) @ 1.5 ml l^-1 which reduced the leaf blast severity by 45.34 per cent and neck blast severity by 16 per cent and increased the yield by 26.9 per cent could be effectively utilized for the control of blast.