The present article describes the development of an indigenous technology for large scale production of ¹³¹I based on the neutron irradiation of TeO₂ target followed by the separation of ¹³¹I using dry distillation technique. In one batch, typically 180 g of natural TeO₂ was irradiated for a period of 21 days in a thermal neutron flux of ~ 5X10¹³ ncm ^-2s^-1, which after chemical processing provided ~ 1.85 TBq (50 Ci) of ¹³¹I. The suitability of ¹³¹I for medical application was evaluated scrupulously in order to ensure compliance with stipulated pharmacopoeia requirement.