Papmochani Ekadashi is a Hindu festival that falls on the eleventh day of the dark fortnight of Chaitra month (March-April). It is the last Ekadashi of the year and it comes between Holika Dahan and Chaitra Navratri. Papmochani means "the remover of sins" and Ekadashi means "the eleventh day". Therefore, Papmochani Ekadashi is a day to worship Lord Vishnu and seek his forgiveness and liberation from sins.

According to Hindu scriptures, Papmochani Ekadashi was first observed by a sage named Medhavi, who was the son of Chyavana Rishi. Medhavi was a devoted follower of Lord Shiva and he used to meditate in a forest for long periods. One day, he was disturbed by a celestial nymph named Manjughosha, who was sent by Indra, the king of gods, to test his celibacy. Manjughosha seduced Medhavi with her beauty and charm and made him forget his meditation. They spent many years together in blissful ignorance until one day Medhavi realized his mistake and felt ashamed of his actions. He asked Manjughosha to leave him but she refused. She said that she had fallen in love with him and wanted to stay with him forever. Medhavi then cursed her to become an ugly witch and she ran away in fear.

Medhavi returned to his father's ashram and confessed his sin. Chyavana Rishi was very angry with his son and cursed him to suffer from leprosy for twelve years. He also told him that he could only get rid of his sin by observing Papmochani Ekadashi Vrat with full devotion. Medhavi followed his father's advice and performed the fast sincerely. He also worshipped Lord Vishnu with flowers, fruits, incense, lamps, etc. He chanted Vishnu's names and recited Vishnu Sahasranama (thousand names of Vishnu). He stayed awake at night singing praises of Vishnu and listening to his stories.

On the next day, he broke his fast after offering food to Brahmins (priests) and poor people. He also donated clothes, cows, gold, etc., as per his capacity. As soon as he completed his fast, he was cured of leprosy and regained his original form. He also attained peace of mind and liberation from sins.