Located at ThillaiGanga Nagar, this very powerful, ancient, beautiful and popular temple located in a two tiered house in a narrow street. Sri Lakshmi Sametha Sathyanarayana Perumal temple is on the ground floor of the Raja Rajeswari temple. Those who are unable to do Sathyanarayana Pooja at home can participate in the pooja here. Sri Lakshmi normally seen by the side of Perumal is present here in the chest of Perumal who is in a standing posture facing west. Navagrahas, normally not seen in Perumal temples are seen here in a straight line which is unique. Panchamuga anjaneyar is also present here.Because of Raja Rajeswari temple, this place was called Nangai Nallur and later became Nanganallur.
It is said that the main deity here came up from a Homa kundam. In a small house in George Town ,Chennai, on Navarathri Friday, on Visaka Nakshtra in 1957, in a mini yagasala atop a house, Rajagopala Swamigal, the founder of Rajarajeswari temple, was immersed in performing homam to Devi.Hundreds of devotees thronged the house to seek the blessing of the goddess. Rajagopala Swamigal completed poornahuti and distributed prasadam to everyone gathered. Suddenly, one of his assistants emerged from the pooja room and pointed to some stones glittering in the agni of the homa kundam.He found stones with blinding brilliance amidst the flames of the agni. The swamigal placed a tray to collect the stones from the agni.The holy stones became heavy once they touched the tray. As a result, the tray also became heavy and tilted to one side, unable to bear the weight. The next day the swamy showed it to the sage of Kanchi, the Paramacharya. The spiritual preceptor promptly identified that the big stone as Ambal and other small stones as Siddhi manigal. Within a year, the big stone took the shape of goddess Rajarajeswari sporting a shanku, chakaram sugarcane, bow and pushpa banam.Rajagopala Swamigal, by divine order, built the temple and ashram in Thillai Ganga Nagar, Nanganallur. He then consecrated the icon of goddess Rajarajeswari which is the presiding deity and poojas are performed according to Srividya sampradaya.
Devotees should go around the temple in anti-clockwise direction. 43 Yantras of Shakti deities are installed in the temple and there are 16 steps to this sanctum sanctorum each with a significance. Sanganidhi and Padmanidhi bless the devotees at the entrance of the steps.
The temple is also called Sarvamangala Sri Rajarajeswari Ashram.