Australians Andrew Chan and Myuran Sukumaran were among the more than 1600 people executed last year - marking a 25-year global record.
The 1634 executions that Amnesty International recorded in 2015 across 25 countries, increased by 573 over the previous year.
China, Iran, Pakistan, Saudi Arabia and the United States are the countries which carry out the most executions, according to Amnesty's annual report card released on Wednesday.
In Australia's immediate region, Indonesia faced heavy criticism for executing 14 people - including Chan and Sukumaran - for drug trafficking, an offence Amnesty says does not meet the threshold of "most serious crimes".
Indonesian courts imposed a further 46 new death sentences in 2015, a sharp increase on the previous year's total of six.
Amnesty noted Indonesia was proactive about lobbying on behalf of its own nationals facing death sentences in other countries, such as Saudi Arabia.
Papua New Guinea has 13 people on death row and there are also concerns the death penalty is on offer for offences that don't fall into the "most serious crime" category.
Amnesty spokeswoman Rose Kulak attributed the 25-year peak in executions to the perceived and real threats of terrorism.
"Governments have used the (war on terrorism) as an excuse to execute people," she told AAP.
Ms Kulak pointed out that Pakistan had a moratorium on the death penalty for seven years before resuming executions in December 2014.
The decision was in response to a Taliban attack on a school in Peshawar in which 141 people, including 132 children, died.
"It's a horrendous cycle that governments get into, where they think killing people is going to be a solution," Ms Kulak said.
Execution figures remain a state secret in China but Amnesty estimates they number into the thousands annually.
Ms Kulak said Australia should be using its close economic ties to lean on China to be more transparent and phase out the practice.
There was some good news in the report, with Madagascar, Fiji, Suriname and Congo abolishing the death penalty - bringing to 2012 the number of like-minded nations world wide.
A parliamentary inquiry is examining Australia's efforts to convince other countries to abolish the death penalty and is expected to release its report in the next couple of months.
DEATH PENALTY FACTS
* 1634 people were executed during 2015, 573 more than recorded in 2014.
* Nearly 90 per cent were carried out in Iran, Pakistan and Saudi Arabia.
* China carries out the most executions but it doesn't publish its numbers. Estimates run to the thousands each year.
* At least 20,292 people were on death row worldwide at the end of 2015.
* Madagascar, Fiji, Suriname and Congo abolished the death penalty in 2015.
* A total of 102 countries have abolished the death penalty.
* Methods of executions include beheading, hanging, lethal injection and shooting.
WHICH COUNTRIES CARRIED OUT THE MOST EXECUTIONS IN 2015?
* China (?)
* Iran 977+
* Pakistan 326
* Saudi Arabia 158+
* United States 28
* Iraq 26+
* Egypt 22+
* Somalia 25+
* Indonesia 14
(SOURCE: Amnesty International report)
