All the seventeen bromo thiazoles have been screened for both fungicidal and bactericidal action. For fungicidal assay, the method of Montgomery and Moore7 was used. Piricularia oryzae Cav., the causative organism of rice blast, was used as the test fungus. The compounds 4(p-hydroxy phenyl), 4(a-naphthyl) and 4(p-bromo phenyl), 5-bromo thiazoles completely inhibited spore germination at concentrations of 20, 20, 22 p.p.m. respectively, and at concentrations of 10, 12, 10 p.p.m., spore germination was only 50 per cent. The unbrominated thiazoles inhibited spore germ :r. at ion at a concentration of 90 p.p.m. The Rideal-Walker serial drop dilution method was used for the study of the antibacterial activity. The test organism wan a 24-hr, culture of Staphylo-coccus aureus. While some of the unbrominated thiazoles were active in 1 : 8,000 (M.E.D.) dilution, 4(m-amino phenyl), 4(p-ethoxy phenyl), 4(oc-naphthyl) 5-bromo thiazoles showed activity in 1 : 20,000 (M.E.D.) dilution, and 4((3-naphthyl), 4((3-phenyl ethyl) 5-bromo thiazoles showed activity at a dilution of 1 : 15,000.Details of this work will bo published elsewhere. I thank Dr. M. K. Rout, reader in chemistry, for his interest and help in the work, and Mr. 8. Y. Padmanavan, mycologist of the Central Rice Research Institute, Cuttack, for supplying the culture of the test fungus for the fungicidal work.