A Goddess Girigujambal is believed to be worshipping Shiva here with goddesses Lakshmi, Saraswathi, Ganesha, Muruga, and Shasta. Maha Bhairava is still believed to be guarding and assisting the divine mother during her prayers. The Goddess is said to be Swayambu as she is present in the form of Meru. Hence, no abhishekam (ablution) is performed for the image. As per a Hindu legend, Indra was cursed by sage Gautama as he misbehaved with the latter's wife Ahalya. To obtain deliverance from the sage's curse, it is said that Indra worshipped Giri-Gujambigai with a scented material termed Punugu for 45 days.
Sages like Gautama and Parashara and kings like Bhagiratha and Nala are said to have worshipped Naganathar at this place.The name "Kumbakonam", roughly translated in English as the "Jug's Corner",is believed to be an allusion to the mythical pot (kumbha) of the Hindu god Brahma that contained the seed of all living beings on earth.
The kumbha is believed to have been displaced by a pralaya (dissolution of the universe) and ultimately came to rest at the spot where the town of Kumbakonam now stands. The drops of nectar are believed to have fallen onto five shrines around Kumbakonam, namely Mahlingeswarar temple at Tiruvidaimarudur, Tirudharasuram, Naganathar Temple at Tirunageswaram, Tiruvorgam and Tirupadalavanam.
The Brahmotsvam or prime festival is celebrated for ten days in the Tamil month of Karthigai (November–December). There is a procession in silver vehicle, marriage festival of the presiding deity, another procession around the streets of Tirunageswarm in temple chariot, sanctification in temple tank and concludes with Vidayathri (farewell function) when a flower palanquin takes the images of the temple deities around the temple. The festival is celebrated amidst music with nagaswaram (pipe instrument) and tavil (percussion instrument) and religious instructions in the Vedas (sacred text) and Tevaram read by priests. Kandasashti festival is celebrated for six during October or November every year when Murugan, the son of Shiva, symbolically kills the demon Surapadma.
The scene is enacted in the South street of the temple during the festival. As per local legend, Rahu got relieved of his pains praying to Naganathar during a Shivaratri day and the day is celebrated in the temple. Navarathri festival is celebrated for nine days for Girigujambigai and the images of Naganathar and Girigujambigai is taken in horse chariot on Vijayadasami, the concluding day of the festival. Sekkizhar Vaikasi Pooja is celebrated from 1969 on the birth date of Sekkizhar, the author of Periya Puranam, the epic describing the life history of the 63 nayanars. Rahu Peyarchi is a festival celebrated once every 1.5 years on the star when Rahu switches its planetary position from one raasi (galaxy) to the other.
The ablution of the image of Rahu during Rahukaalam with milk turning to blue colour in this temple is considered to be a miracle and attracts devotees from distant places.
The presiding deity is believed to have been worshipped by many serpent deities like Adiseshan, Dakshan and Karkotaka. As per Hindu belief, people troubled by Sarpa-dosha or Malefic effects Rahu-Kethu seek a relief by offering prayers in a single day to Kudanthai or Kumbakonam Nageshwarar in the morning, Thirunageshwaram Naganathar at the noon, Thirupamburam Pambureswarar in the evening and Nagoor Nageshwarar or Naganathar temple at night.
Tirugnana Sambandar, a 7th-century Tamil Saivite poet, venerated Naganathar in ten verses in Tevaram, compiled as the First Tirumurai. Appar, a contemporary of Sambandar, also venerated Annamalaiyar in 10 verses in Tevaram, compiled as the Fifth Tirumurai. As the temple is revered in Tevaram, it is classified as Paadal Petra Sthalam, one of the 275 temples that find mention in the Saiva canon. The temple is one of the most visited temples in the district. The temple is counted as one of the temples built on the banks of River Kaveri.