Navami starts with a holy bath following which Shodhasopachar puja is done. On this day Devi Durga is worshipped as Mahishasuramardini, meaning the Goddess who killed Mahishasur. It is believed that on this day the demon was finally annihilated. A special ritual of Navami hom is done at the end of Navami puja.
It is also believed that puja done on this day is equivalent to puja done on all the nine days of the Navratri festival.
In some places, ancient tradition of Navami bali or sacrifice of animals is still practiced.