Gas chromatography analysis of a phylogenetically higher termite-gut homogenate detected the presence of trace amounts of poly(3-hydroxybutyrate) (PHB), a prokaryotic storage material. In addition, the gut homogenate smear, stained with Nile blue A, also suggested the presence of PHB-like granules. Chloroform extracts of both soldier and worker classes of this termite were obtained for further spectroscopic analysis. FTIR, 1H NMR, and 2D 1H-1H NMR analyses confirmed the presence of PHB in both the chloroform extracts. This showed for the first time the occurrence of bacteria capable of accumulating PHB in the termite gut. The results indicated that the physiological environment in the termite gut is suitable for the colonization by PHB-producing bacteria and is probably rich in organic carbon sources, which can be readily assimilated and stored as PHB.Key words: Macrotermes carbonarius, poly(hydroxyalkanoate), PHB, termite