The news site Europaportalen went through the 20 Swedish MEPs' attendance at the committees they sit on, and found that on average the politicians only showed up about half of the time.
The finding worried EU experts in Sweden, as committee work was deemed essential to the work of the parliament, which holds sessions in Brussels and Strasbourg.
"Committee work is very important because that's where legislative work takes place," European politics researcher Göran von Sydown at Sieps told Europaportalen.
The worst offender was the Christian Democrat parliamentarian Alf Svensson, who defended himself by saying that the review gave an incorrect picture of his work.
"I sit on two committees and often these two committees hold meetings at the same time," Svensson said of his less than 50 percent attendance rate.
The most active Swedish MEP, however, was the Greens' Isabella Lövin, famous for fighting for fishing quotas last year. Another MEP with near perfect committee attendance was the Liberal (Folkpartiet) Marit Paulsen.