Despite Mr MacAskill's insistence to the contrary, more than two thirds of those questioned - 68% - thought the decision was influenced by factors other than Megrahi's health, while only 20% believed it was made purely on compassionate grounds.
Mr MacAskill's controversial meeting with Megrahi in Greenock Prison on 4 August was also unpopular, according to the poll, with 52% believing the visit should not have taken place, and 36% saying it should.
The justice secretary has claimed the visit was required under the terms of the Libyan government's prisoner transfer request, but this has been disputed by opposition politicians
Almost three quarters of those polled (74%) said the affair had damaged the standing of the Scottish Government in the eyes of voters, with the same proportion believing the release of Megrahi had damaged Scotland's reputation.
Only 11% said it had enhanced the reputation of the country, while 10% said it had made no difference one way or the other.
Prime Minister Gordon Brown has also apparently been damaged by the controversy over the release of Megrahi, despite his insistence that it was purely a matter for the Scottish government.
The poll suggested that 34% believed Mr Brown's reputation had been damaged "a lot", with a further 33% saying it had been damaged "a little".
But only 29% of those surveyed said the prime minister had not been damaged.
A minority of people - 39% - said they thought the UK government should have tried to influence the decision by the Scottish Government, while 52% said it was right not to get involved.
Responding to the poll findings, First Minister Alex Salmond stood by his justice minister.
He said: "I acknowledge that these were difficult, controversial decisions but somebody had to take a decision and it fell to the Scottish Justice Secretary, Kenny MacAskill, to do so.
"Sometimes in life and politics and in government, there's no easy option available. You have to take hard choices because you think and believe you're doing the right thing and you know it just takes guts to govern sometimes and Kenny MacAskill showed that."
Scottish Labour leader Iain Gray called on Mr Salmond to explain how he would repair Scotland's damaged reputation.
He added "I believe the whole process was mishandled from start to finish and a clear majority say it was wrong for Mr MacAskill to visit Megrahi in prison. Kenny MacAskill must return to the parliament to justify his mishandling of this affair."
Annabel Goldie, leader of the Scottish Conservatives, said the findings showed the Scottish Government was wrong to release Megrahi - and she demanded to know what "murky deals have been going on behind the scenes".
For the Liberal Democrats, MSP Mike Rumbles said the poll confirmed public anger at the SNP's handling of the affair and its failure to address other options for the "compassionate" treatment of Megrahi.
Megrahi, who has always maintained his innocence, was the only person convicted over the Lockerbie bombing.
He returned to a hero's welcome in Libya after being released from Greenock Prison.
The release sparked widespread criticism in the UK, as well as from US politicians, law enforcement agencies and victims' relatives.
An internet campaign was also launched calling on Americans to boycott Scottish and UK goods over the release.
This page is best viewed in an up-to-date web browser with style sheets (CSS) enabled. While you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. Please consider upgrading your browser software or enabling style sheets (CSS) if you are able to do so.