Constructed in the Dravidian style of architecture, the temple is glorified in the Nalayira Divya Prabandham, the early medieval Tamil canon of the Alvar saints from the 6th–9th centuries CE.

It is one of the 108 Divya Desams dedicated to Vishnu, who is worshipped as Purushothaman Perumal (also called as Purushothamar) and his consort Lakshmi as Poornavalli Thayar.

The temple is believed to have been built by the Medieval Cholas of the late 8th century CE, with later contributions from Vijayanagara kings and Madurai Nayaks.

As per Hindu legend, the god Vishnu emerged as a Kadamba tree here, giving the name Kathambanur, which later became Karambanur.

[2][3] According to another Hindu legend, the temple is believed to have been constructed by Janaka, the king of Janakapuri and the father of the goddess Sita.

The temple is believed to have been built by the Medieval Cholas of the late 8th century CE, with later contributions from Vijayanagara kings and Madurai Nayaks.

The temples has images and separate shrines for Purushottamar (Vishnu), Bhikshadanar (Shiva), Brahma and their respective consorts Poornavalli (Lakshmi), Soundarya Parvati and Saraswati.

The central shrine facing East houses the image of Vishnu, as Purushottamar, in reclining posture, similar to the idol of Ranganatha at the nearby temple in Srirangam with the discus in one hand and the procession idols of Vishnu, Lakshmi and Bhumi (Earth goddess).

The temple rituals are performed six times a day; Ushathkalam at 5:30 a.m., Kalasanthi at 8:00 a.m., Uchikalam at 10:00 a.m., Sayarakshai at 5:00 p.m., Irandamkalam at 7:00 p.m. and Ardha Jamam at 8:30 p.m.

The worship is held amidst religious instructions in the Vedas (sacred texts) read by priests and prostration by worshippers in front of the temple mast.

[2] The temple is revered in Nalayira Divya Prabandham, the 7th–9th century Vaishnava canon, by Thirumangai Alvar in ten hymns.

[7] Periyavachan Pillai, who translated the verses of Thirumangai Alvar, glorifies the temple as "the one without doors where devotees can always visit and worship".