Pakistan lifted a moratorium on executions in late 2014 as a measure to deter militancy, after a Taliban gunmen attacked a school and killed 134 students and 19 adults.
Pakistan now ranks after China and Iran, carrying out 324 hangings in 2015 alone, the report showed.
Juveniles, mentally ill prisoners, and prisoners who had been tortured or had not received fair trials were among those executed, the report found in an analysis of media reports and data from courts, prisons and legal teams.
“The numbers show that the Pakistan government’s claims do not match reality,” said Maya Foa, director of the death penalty team at Reprieve.
“Those going to the gallows are too often the poor and vulnerable,” she said in a statement. “It is hard to see how hanging people like this will make Pakistan safer.”
A spokesman from Pakistan’s interior ministry did not respond to requests for comment.
The government initially said the unofficial moratorium was only being lifted in cases connected to militancy, but it was later broadened to cover all cases, the report said.
The hangings have drawn condemnation from international partners but have been broadly popular at home.
Government officials told Reuters last year that the policy had been helping to deter militant attacks.
Militant, insurgent and sectarian attacks have fallen since 2014, though it is unclear whether the decline is linked to the change in execution policy, as it has also coincided with a military crackdown on militant strongholds.
Last year, attacks in Pakistan by militant, insurgent and sectarian groups were down 48 percent from 2014, an independent think-tank, the Pak Institute for Peace Studies, says.