The ban is being imposed at the Kumbh Mela, a pilgrimage that has attracted nearly three million people since July.
Authorities say that selfies will be banned on the days that people ritually bathe in the sacred Godavari river.
Organisers say they conducted a study that showed people took too long taking selfies. This slows down the flow of people, leading to pushing and panic.
Signs saying "no selfie zone" can be seen around the two festival sites in the state of Maharashtra.
The festival takes place every three years. It began in mid-July and runs until late September.
The decision was taken after over 100 volunteers conducted a study on behalf of the Kumbhathon group which works with the authorities to help monitor the festival.
"Since 13 July, our volunteers on the field have been collecting data which showed that people stop to take selfies. They also climb to dangerous spots to take selfies," Kumbhathon CEO Sandip Shinde told the Indian Express.
Local official Dr Pravin Gedam told the paper that selfies would only be banned during the "days of the holy dip as we don't want to take away from the festive mood on other days".
A "no selfie zone" will be implemented at a major Hindu festival in India due to fears they could cause stampedes.