Abstract Tamarind seed coat tannin was extracted and its tannin class was determined. The extracted tannin was employed as a natural mordant alone and in combination with metal mordant namely copper sulphate for cotton, wool and silk fabrics and dyed using natural dyes namely tur- meric and pomegranate rind. The colour strength, colour coordinates, wash and light fastness were evaluated and compared for all the three fabrics with and without mordanting. The pre-mordanted fabrics on dyeing gave better colour strength, wash and light fastness than those dyeing obtained without mordanting. The total phenolic content of the extract was calculated and minimum inhibi- tion concentration was 1% against both the Staphylococcus aureus and Escherichia coli bacteria. The mordanted and dyed fabrics resulted in good antibacterial activity up to 20 washes, when nat- ural mordant was used along with 0.5% and 1% copper sulphate mordant and dyed with natural dyes.