A study was conducted to assess the effects of rice dietary fibre on the fermentative activity of human faecal microflora. Dietary fibre was extracted from four commercially available Sri Lankan rice varieties [LD 356, AT 353 (red in colour); BG 352, and BG 358 (white in colour)], and separated into individual fractions of total dietary fibre (TDF), insoluble dietary fibre (IDF) and soluble dietary fibre (SDF). Four healthy human subjects were given a diet containing the four rice varieties for more than 4 months prior to the study. Faecal microflora was obtained from human volunteers, after the 4 months of rice based diet, and used for anaerobic fermentation of the individual rice fibres. Short Chain Fatty Acid (SCFA) production was analysed at 0, 2, 4, 6 and 24 h by gas liquid chromatography. Among the SCFA, acetate was the most abundant acid formed in all rice varieties. The fibre fractions from rice variety LD 356 (TDF16.73%, SDF 3.57%, 11.9% IDF) gave the highest yield of SCFA while the variety BG 358 gave the least. Total dietary fibre of all rice varieties contributed to produce more SCFA than the individual soluble dietary fibre and insoluble dietary fibre fractions.