General elections were held in Sweden on 17 September 2006, to elect members to the Riksdag, the Swedish national legislature. All 349 seats were up for election: 310 fixed seats in 29 constituencies and 39 adjustment seats, used to ensure that parties have representation in the Riksdag proportional to their share of the national vote. The electoral system used was semi-open list proportional representation using the Sainte-Laguë method of allocating seats. Elections for County and Municipal councils were also held on the same day.