- Unicameral parliament
- Name: Parliament (Riksdagen)
- Members: 349
- Term: 4 years
- Constituencies: 29 multi-member constituencies for 310 members (2 to 34 seats each; the number of seats per constituency is revised at each election based on the number of eligible voters); 1 other multi-member constituency for 39 "at large" seats.
- Voting system: Proportional (for 310 seats): members are elected under the closed-party list system with preferential vote. Seats are proportionally distributed according to the modified Sainte-Laguë method. To be awarded a seat, a party must obtain either at least 4 per cent of the votes cast throughout the country or 12 per cent of the votes cast in a constituency. Votes are cast for party lists, and electors may also express specific preferences for individual candidates. In such cases, the required threshold for election on the basis of personal votes is 8 per cent of the total cast for the candidate's party in the constituency concerned. For the 39 remaining ("at-large") seats: the remaining seats are allotted by the system of full proportional representation based on the votes obtained nationwide; to be awarded a seat, a party must obtain at least 4 per cent of the votes cast throughout the country.
- Voter requirements: 18 years of age; Swedish citizenship (including naturalized citizens); there is no residence requirement; citizens overseas can vote under certain conditions: they must be on the special electoral roll, which includes citizens who have emigrated during the past ten years or who have notified the tax authorities of their wish to be on the electoral roll no later than 16 August of the election year (non-registered citizens may still be included in the electoral roll on condition that their ballot paper arrives before 14 September of the election year).
- Voting is not compulsory.
Prime Minister Fredrik Reinfeldt's centre-right coalition (the Alliance, consisting of M, C, FP and KD) won 173 seats in a definitive recount issued by the election commission on Thursday 23 September 2010, versus the 172 announced on election night (19 September), but fell short of the 175 seats needed for a majority.
The Alliance bloc beat the Social Democrat-led opposition (SAP, MP and VP) by a wide margin, but lost its majority because the anti-immigrant Sweden Democrats, shunned by both blocs, won their first seats in parliament. Reinfeldt has said he will reach out to the opposition Green Party for support, but the Greens have said their voters would not approve of such a link, meaning the centre-right will probably need to cobble together majorities bill by bill.
Fewer than 2,000 votes separated Reinfeldt's coalition and the total of all other parliamentary parties, the final tally showed.