Ksharsutra can be defined as an Ayurvedic medicated thread coated with herbal alkaline drugs. ‘ Ksharsutra therapy ‘ has been described as a treatment of choice for the treatment of fistula in ano due to low recurrence rate. Fistula in ano is a condition which has been recognised as a difficult surgical disease in all the ancient & modern medical sciences of the world. Besides Fistulectomy, Sushruta the father of surgery has also described its treatment by Ksharsutra method considering it as Nadi vrana. To overcome the recurrence in Fistula in ano & hospitalization in Fistulectomy & Fistulotomy procedures a Ksharsutra is a magical result in Fistula in ano.