The SOM survey, conducted in the autumn of 2009, shows that 36 percent of Swedes consider that there are too many foreigners living in Sweden. In 1993 the figure was 52 percent.
"Never before have Swedish attitudes been so accepting as their are now," Professor Marie Demker wrote in an opinion article in the Dagens Nyheter daily on Monday.
In 1993, 25 percent replied that they would not like an immigrant from another continent marrying into the family, this figure had dropped to 12 percent in the autumn.
"Despite the attempts to mobilize, groups which oppose immigration remain a peripheral sub-culture," Demker wrote.
Among the parliamentary parties, supporters for the Moderates are most sceptical while those who back the Green Party are the most enthusiastic supporters of immigration.
Support for the right of immigrants to freely practice their religion has not changed since 1993, and remains at around 40 percent among Swedes. Supporters of the Liberal Party (Folkpartiet) have, however, become less tolerant of immigrants' religious practices today than 17 years ago, although it remains above average at 41 percent.
Supporters of the far-right Sweden Democrats (SD), who strive to make immigration an election issue, show the lowest levels of tolerance towards both immigrants and refugee centres, representing a clear exception in the SOM institute survey.
Among SD supporters, 95 percent agreed with the statement that Sweden "should accept fewer refugees" compared to 46 percent of the population as a whole. Eighty-eight percent agreed with the statement that there "are too many foreigners in Sweden" as compared to 36 percent of the population as a whole.
Since 1993, SOM has monitored Swedish attitudes to immigration and refugee centres on six occasions. The surveys are based on a series of standardized so-called tolerance claims.