Curcuma longa L. is a spice crop with enormous medicinal and cosmetic properties cultivated across the world. It was propagated vegetatively by means of rhizomes, as these were underneath soil prone to soil borne fungal diseases. Treatment of such diseases using chemical fungicides would hinder their nutritional and medicinal value. To overcome such challenges, there are a few alternatives, the major among them was the deployment of disease-free in vitro raised plantlets and the other was biopriming of these plantlets with Trichoderma viride. Besides fungicidal action, T. viride has a prominent role in alleviating several biotic/abiotic stresses and it was more often used during acclimatization. In this study, we studied the role of T. viride on successful acclimatization of in vitro C. longa plantlets by modulating plant antioxidant defense systems. We determined the stress levels (MDA and chlorophyll contents) and monitored the antioxidant enzyme activities (CAT, APX and GR) in both T. viride-treated and untreated micropropagated plantlets at four different time points (0, 15, 30, 45, 60 days) of acclimatization period. Our results depicted clear enhancement in the antioxidant enzyme activities in T.viride treated than untreated plantlets, which signify the role of T. viride in activating defense mechanisms to combat against oxidative stress. Thus this study would give clear understanding of the influence of T. viride on in vitro raised plantlets in sustaining adverse acclimatization conditions.