The goal of this experiment is to enhance the nutritive value and reduce tannin concentration of tamarind seeds collected from semiarid parts of Indonesia by yeast fermentation. The tamarind seeds were first dried in sun light and powdered using pulverizer. The kernel flour was used for yeast fermentation for 12 and 24 hours with 5 repetitions. The crude fiber, amino acids, fatty acids and tannins of pure kernel flour and fermented kernel flour were compared. Data were analyzed by using Analysis of Variance (ANOVA). The proximity analysis showed that tamarind seeds kernel flour contains crude protein 16.2%, fats 7.06 %, crude fiber 17.7 %, Nitrogen Free Extract (NFE) 57.88% and ash 1.16%. HPLC analysis of crude protein showed the presence of 16 types of amino acids (13.3 mg/100g protein). Gas chromatography was used for finding the composition of fatty acids (74.1 mg/100g fats) and tannin concentration (300mg/100g of kernel flour). The fermentation increased the crude protein and amino acids content and lowered the concentration of fatty acids and tannins. Fermentation with Saccharomyces cerevisiae in kernel flour for 12 hours is comparatively more effective than 24 hours to lower tannins content and improve nutritive value.