The original Senate consisted of 40 members, the majority of whom were elected by the House of Assembly, the directly elected lower chamber, with the remainder being chosen by the Council of Chiefs and appointed by the President. Under the Lancaster House Agreement, 20 per cent of seats in both chambers were reserved for whites, until 1987. It was abolished by constitutional amendment in 1989, with many Senators being appointed to the House of Assembly.
The re-introduced senate, formed following the elections held on 26 November 2005, had a total of 66 members. 50 members (5 from each province), directly elected in single member constituencies using the simple majority (or First-past-the-post) system. The President appointed 6 additional members and the remaining 10 seats were held by traditional chiefs who were chosen in separate elections. Twenty-one women (20 elected and 1 appointed) occupy seats in the Senate.
Constitution of Zimbabwe Amendment No. 18 of 2007 provided for the expansion of the Senate to 93 seats: 6 (six) Senators from each province directly elected by voters registered in the 60 Senate constituencies; the 10 Provincial Governors appointed by the President; the president and deputy president of Council of Chiefs; 16 chiefs, being two chiefs from each province other than metropolitan provinces, and five Senators appointed by the President.
The composition was again changed following the 2013 constitution. The current Senate consists of 80 members, of whom 60 are elected for five-year terms in 6-member constituencies representing one of the 10 provinces, elected based on the votes in the lower house election, using party-list proportional representation, distributed using the hare quota. Additionally the Senate consists of 2 seats for each non-metropolitan district of Zimbabwe elected by each provincial assembly of chiefs using SNTV, 1 seat each for the president and deputy president of the National Council of Chiefs and 1 male and 1 female seat for people with disabilities elected on separate ballots using FPTP by an electoral college designated by the National Disability Board.