Emblica officinalis G. dried fruit tannin was extracted and applied as a natural mordant alone and in combination with metal mordant namely copper sulphate for dyeing on cotton and silk fabrics using natural dyes. The color strength, color-coordinates, wash and light fastness were also evaluated for cotton and silk fabrics with and without mordanting. The pre-mordanted cotton and silk fabrics on dyeing gave better color strength, wash and light fastness than those dyeing obtained without mordanting. The total phenolic content of the extract was calculated. Cotton and silk fabrics resulted in good antibacterial activity using the Emblica officinalis G. mordant. When mordant was used along with 0.5 and 1 % copper sulphate mordant and the activity enhanced and was active up to 20 washes.