More than 100 others were injured in the tragedy at the Ratangarh temple in Datia district, 390 km north of this state capital and 55 km from Datia town.
An estimated 2.5 lakh people had gathered all around the Maa Ratangarh Wali temple on the last day of Navratri festival, a police officer said. About 35,000 people were at the site of the tragedy.
The temple is located in a dense forest on the banks of Sindh river. It draws thousands during Navratri, the bulk making it on the last day of the nine-day festival.
Just how the stampede happened was not clear.
One version -- denied by the authorities -- said a police baton attack over a narrow bridge over a river caused the tragedy.
Another version said a rumour that the bridge was collapsing triggered a mad rush, resulting in the stampede.
As men, women and children fell and got crushed, some of the devotees jumped from the bridge into the fast flowing river.
Deputy Inspector General of Police D.K. Arya told IANS that the death toll was likely to rise as many pilgrims were critically injured.
He added that some were missing after falling off the bridge.
Madhya Pradesh Chief Secretary Antony Disa put the death toll in the evening at 85 and pledged to take action against those responsible for the stampede.
He said more than 20 bodies had been flushed out of the river.
Some devotees complained that the number of policemen deployed to control the crowds was grossly inadequate.
Chief Minister Shivraj Singh Chouhan announced a compensation of Rs.1.5 lakh to the kin of each of those killed.
Datia legislator Narottam Mishra, who is also the state government spokesman, blamed the stampede on a rumour that the bridge on the river near the temple was collapsing.
An angry crowd later stoned police personnel, injuring 12 men, including two officers.