The temple is a classical example of the architectural style of Kerala and has one monumental tower on each of the four sides in addition to a koothambalam.

The temple, along with the mural paintings, has been declared as a National Monument by India under the AMASR Act.

Thekkinkadu Maidan, encircling the Vadakkumnathan Temple, is the main venue of the renowned Thrissur Pooram festival.

[6] Though these accounts differ with respect to certain details, they are all in agreement regarding the central theme that the temple was founded by Parashurama.

According to lore, Parashurama requested the Lord of oceans Varuna to bring forth a new piece of land from the waters.

So he went to Mount Kailasa to his guru, the god Shiva and requested him to take abode in Kerala and thereby bless the region.

Shiva accompanied by his wife Parvati, his sons Ganesha and Subrahmanya and his routinue went along with Parashurama, to oblige his disciple.

Later he and his party disappeared and Parashurama saw a bright and radiant Lingam (non-anthropomorphic icon of Shiva) at the foot of a huge banyan tree.

Adi Shankara is believed to have been born (509 BC) to Shivaguru and Aryamba of Kalady consequent to their prayers to Lord Vadakkumnathan, as amsavatara of Shiva.

[12][13] According to legend, Adi Shankara attained videha mukti ("freedom from embodiment") at the Vadakkunnathan temple.

According to historical accounts, when Tipu Sultan was marching towards the Travancore lines, known locally as Nedumkotta, he had a short stay at Thrissur city from 14 to 29 December 1789.

Before leaving Thrissur city, he not only returned the vessels, but presented the temple with a large bronze lamp.

He later cleared the teak forest around the temple and introduced the famous Thrissur Pooram festival.

The temple is situated on an elevated hillock in the centre of Thrissur City and is surrounded by a stone wall enclosing an area of nearly 9 acres (36,000 m2).

According to traditional belief, the ghee-covered lingam represents the snow-clad Mount Kailash, the abode of Shiva.

Between these two sanctums (srikovils) stands a third one, circular and double-storied in shape, which is dedicated to Shankaranarayana, the combined form of Shiva and Vishnu, facing west.

The two important murals – which are more than 350 years old – in the temple, Vasukisayana (reclining Shiva) and Nrithanatha (20-armed Nataraja), are worshipped daily.

Outside the main temple, there are shrines for the two sons of Shiva and Parvati – Subrahmanya (Kartikeya) and Ganapathi (Ganesha).

The Subrahmanya Temple under Manikantan Aal, which is located at the south-western side of Vadakkumnathan Temple, was built by some local devotees who were furious by the continuous speeches of political leaders during Indian Independence Movement happening under Manikantan Aal.

The main deity, Lord Ganapathi, is installed facing west, in a mode of welcoming those entering the city from the western side.

He gave this task to Velanezhy Nambudiri, a famous Thachushasthranjan or master craftsman, who built the structure.

It has been the regular annual practice at the temple for the last 20 years to conduct a large-scale Ashta Dravya Maha Ganapathy Havana and Aanayoottu on the first day of the Karkidakom month of the Malayalam calendar.

It involves a number of unadorned elephants being positioned amid a multitude of people for being worshipped and fed.

The deities from Parmekavu and Thiruvambady temple along with other small poorams come engage in festivities in front of Vadakkumanathan.