Triphala, a mixture of Emblica officinalis, Terminalia chebula, and Terminalia bellirica, containing ingredients from plant origin, is often prone to microbial contamination. A high level of microbial contamination was observed in Triphala samples obtained from different sources. On gamma radiation processing, a sharp decline in log CFU was observed with increasing radiation dose and a complete decontamination at 5 kGy. Average D10 value for total aerobic and fungal counts were observed to be 0.55±0.073 kGy and 0.94±0.043 kGy, respectively. Water extracts of irradiated samples showed linearly increasing concentration of gallic acid (3.3 to 4.5 times), total phenolic contents (2.16 to 2.87 times), and antioxidant properties with increasing radiation dose up to 25 kGy. The increase could be attributed to easy release of active ingredients from their radiation degraded complex forms. Aflatoxin B1 and ochratoxin could not be detected in the samples. Gamma-radiation dose up to 5 kGy could be safely used to hygienize Triphala.