Only 39 percent of Swedes think it's a 'good idea' that Sweden is in the European Union, pollsters found, compared to 59 percent in autumn 2015.
Meanwhile 21 percent said they thought EU membership was a 'bad idea', while the remainder suggested they were unsure.
The huge fall in support for the European project is most likely due to the ongoing refugee crisis, experts told SVT as the findings were released on Monday.
“People are listening to public officials and in Sweden there has been criticism from politicians on what the EU does and does not do when it comes to the refugee crisis,” Göran von Sydow, a political scientist and researcher at the Swedish Institute for European Policy Studies, said.
Sweden's Social Democrat Prime Minister Stefan Löfven last year repeatedly asked other EU nations to grant more people asylum as his own country took in record numbers of people fleeing war and conflict.
When they didn't act voluntarily, he wrote a letter to the European Commission, asking for some of the refugees arriving in the Nordic nation to be distributed to other countries in the 28-member bloc.
However this idea was thrown out as part of the settlement agreed in March which focused on sending back refugees arriving in Greece from Turkey.
In the meantime, Sweden reinstated border checks and introduced tighter residency rules after local municipalities said they could no longer guarantee accommodation to all new arrivals.
Refugee numbers have dropped dramatically since the shift, with around 500 to 600 people making the journey to Sweden each week, compared to 10,000 last autumn, according to official figures from the country's migration agency, Migrationsverket.
TNS Sifo's poll in Sweden asked 1142 people aged between 18 and 79: “What do you think in general about Sweden being a member of the EU?”
The results emerge as similar surveys in the UK indicate that the upcoming referendum on EU membership will be a close race. A YouGov poll released last week suggested that 40 percent of Brits will vote to remain in the EU, while 39 percent support the country leaving and the rest are undecided or do not plan to vote.