The functional finishing has becoming the most required need for textile materials. In this study an attempt has been made to impart the antimicrobial source on the Bamboo 100%, Tencel 100% and Bamboo/Tencel 50/50 fabrics. The three herbal oils of thyme oil, cypress oil and Grape fruit oil were screened separately with other oils for many functional properties. Selected these, three herbal oils were mixed with four combinations to ensure the best combination for antimicrobial efficacy. The finished fabrics are evaluated using such test methods (AATCC 147, AATCC100). The investigated result states that (2:1:1) ratio shows the best antimicrobial property in all the three fabrics. Among these fabrics Bamboo/Tencel 50:50 fabric shows the best result.