Kartik Maas Poornima, also known as Tripuri Poornima, is considered the most significant of all poornimas, as it is believed on this day, during Pralaya Kaal lord Vishnu incarnated as a fish called Matsya Avatar to save the Vedas.

This day is celebrated by holy bath and donation by the devotees. At the twilight, people light small diyas near Banyan Trees, Tulsi plant and river Ganga. The holy month starts from Sharad Poornima and ends with Kartik poornima. It is believed that a dip in Pushkar, Ganga, Dwarika, Puri or Mathura during this month cleanses the soul.

In Udaipur, people took bath before Sunrise and worshipped lord Vishnu while in the evening, banks of Lake Pichhola lightened up with several diyas.

A devotee, Kamla Devi Vaishnav says that this day is very important for vaishnav religion followers. All the devotees take a holy bath at Gangaur Ghat in he morning and then worship lord Shiv Pathwari. During the pooja, 35 fruits, betel-nut, Panch mewa and kheer are distributed as Prasad. Several people perform fasting during this whole month.

This pooja and ritual has continuously been performed for ages on the day of Kartik poornima at Gangaur ghat.