Hampus Brynolf, head of digital strategy at media group Intellecta that carried out the research, told Swedish Radio that Twitter accounts are increasingly being opened by women, the young and by people living outside Sweden's major cities.
The report, the third of its kind, shows that 475,474 Swedes now have Twitter accounts, a jump of almost 200,000 compared to last year.
Journalists and others in the media still make up the largest number of users, but the fastest growing groups of tweeters include women and young people who use the site to follow celebrities such as their favourite singers and sports stars.
New users tend to just read others' updates, rather than tweeting themselves, with only a small minority sharing their thoughts in fewer than 140 characters very frequently.
Roughly the same number of Swedish men tweet as Swedish women, and the average user follows 73 accounts and has 77 followers.