The most impressive processions are those from the Krishna Temple at Thiruvanbadi and the Devi Temple at Paramekkavu which is quite a significant event for its devotees. This festival was introduced by Sakthan Thampuran, the Maharaja of the erst while Kochi State. Perhaps, there is no other festival in Kerala that draws such an unbelievable number of people to a single event. However Vadakkunnathan is a mere spectator at this festival, lending its premises and grounds for the great event. The pooram festival is also well known for the magnificient display of fire works.
Fire works start in the early hours and the dazzling display last three to four hours.
The Pooram Festival is celebrated by two rival groups representing the two divisions of Thrissur Paramekkavu and Thiruvambadi vying with each other in making the display of fireworks grander and more colourful. Each group is allowed to display a maximum of fifteen elephants and all efforts are made by each party to secure the best elephants in South India and the most artistic parasols, several kinds of which are raised on the elephants during the display. Commencing in the early hours of the morning, the celebrations last till the break of dawn, the next day. The procession of the Thiruvambadi Pooram to the grounds of Vadakkumnatha Temple and back is not only important, but also quite enlivening. The marvellous as well as magical effect of the Panchavadyam, a combination of five precussion and wind instruments is to be felt and enjoyed.