The 2006 Iowa Senate election was held on November 7, 2006. The Senate seats for the twenty-five odd-numbered districts were up for election. Senate terms are staggered such that half the membership is elected every two years. Senators serve four-year terms. Prior to the election, the Senate was evenly divided between Republicans and Democrats. Following the election, the Democrats were in the majority - this marked the first time in 42 years that the Democrats had controlled both branches of the Iowa General Assembly and the Governor's Office.