There is a fascinating legend about the origin of the rituals in this temple. One Ekadesi day, Sri Adi Shankara and Narada were travelling in space above the temple of Guruvayur. Narada told the Acharya that he was descending at Guruvayur. Acharya disdainfully told Narada that idol worship and chanting of the Lord's name repeatedly was for the ignorant and not for a Gyani like him and continued his journey in space. But within a few minutes, he had a fall and lay prostrate on the earth by the northern side of the temple, where the Lord's Sriveli had reached. The Acharya realised his error and begged the Lord for forgiveness. The Lord told him that temple worship, repetition of Lord's name and listening to religious discourses were all ways of expressing devotion and were all dear to him. He then asked Sri Shankara to organise the daily worship in the temple, which he did. These rituals are followed even today.

Everyday, the temple opens at 3 a.m. and the Lord is awakened from his sleep with the melodious notes of nadaswaram. The Lord is seen adorned with flowers of the previous day. This is known as Nirmalya Darshanam. It is believed that celestial beings come and worship the Lord after the temple is closed.

Sriveli is a ritual which is performed thrice every day. The Utsava Vigraha of the Lord (a miniature of the idol in gold) is mounted on an elephant and taken around within the four outer walls of the temple, three times, to the accompaniment of drums. There are beli Kallus representing the Lord's body guards, subsidiary deities and members of his entourage in the inner and outer prakara. The idea of Sriveli and the priest performing poojas at these places is that the Lord Himself standsby as offerings are made to his dependants. Guruvayur is a temple state with the Lord as its Head. Every night at the close of worship, the days account is read to the Lord even today. Another ceremony is the Thulabharam, in which the devotees are weighed against plantains/sugar/jaggery/coconuts or other articles. These are gifted to the temple.

Another is Annaprasanam, first feeding ceremony of the child.