The presiding deity is Bhadrakali, a fierce and benevolent form of Goddess Durga. Locally, she is worshipped as Kodungallur Amma.The temple is believed to have ancient Dravidian origins and is associated with the Chera dynasty, one of the early ruling families of Kerala.

It has strong historical links with Tamil and Sanskrit traditions and was once a prominent center of Tantric worship. According to legend, the temple is located on the site of the original yagna (sacrifice) ground created by Lord Parasurama, the mythical founder of Kerala. The idol of the goddess is said to be installed by Sage Bhargava. The temple was also a place of learning and culture, and played a significant role in the development of Malayalam language and literature, with the poet Cherusseri Namboothiri and other early literary figures connected to the area.
Kodungallur Bharani Festival, held annually during the Malayalam month of Meenam (March–April), is the most prominent celebration at the temple. It commemorates the triumph of Goddess Bhadrakali over the demon Darika. The festival is marked by intense devotional fervor, where thousands of Velichappads (oracles) perform ritualistic dances in a trance, invoking the goddess’s divine presence. Devotees chant the traditional “Bharani Pattu” and enact symbolic rituals representing the slaying of evil. Highlights include sword dances, symbolic animal sacrifices, and vibrant processions, making it one of Kerala’s most powerful and energetic temple festivals.
Thalappoli Festival, usually celebrated in January, is a vibrant, women-centric event. Women and young girls participate by carrying plates filled with offerings, flowers, and lit lamps, forming beautiful processions in honor of the goddess. The ritual is observed to invoke blessings for prosperity, protection, and well-being.Additionally, the temple observes Mandala Pooja and Makaravilakku during December–January, a spiritually significant period with increased pilgrim turnout. Though more subdued compared to Bharani, these days are marked by special poojas and devotional rituals, aimed at spiritual cleansing and seeking divine grace.