The Svenska Dagbladet (SvD) newspaper reported on Thursday that support for potential membership of the military alliance has increased.
Thirty-two percent of survey respondents stated that they were in favour of Sweden joining Nato. Two years ago, that number was 23 percent.
The proportion of Swedes who firmly want to stay out of Nato has gone down in the same period. The new poll showed that two in five Swedes say no to joining, down from 2011 when half of Swedes had the same attitude.
"It looks like Nato proponents have advanced their positions," political scientist Ulf Bjereld told SvD.
He said that debate in recent months about Sweden's military capacity had likely stirred Swedes' thoughts about Nato. The Armed Forces' ability to defend Sweden if it came under attack has been under scrutiny since Supreme Commander Sverker Göransson in January said Sweden could hold out for maximum one week.
The poll also looked at feelings towards Nato within Sweden's different political parties. It found that one in four Social Democrats supported membership, while as many as one in two Moderate Party supporters wanted to join.
While the Moderates are officially in favour of joining, it's the party's coalition ally the Liberals (Folkpartiet) that has at times lobbied for membership and made it a talking point on the political agenda.
Bjereld noted that the principle of non-alliance and neutrality had long been a cornerstone of Swedish national identity.
"To join a military alliance would be a big psychological step for many Swedes, and I also think there is significant concern that Swedes would risk being pulled into warfare against its will," Bjereld said.