First convened in 1973, the Senate's composition and powers are established by the Article 59 of the Constitution of Pakistan. Each four provinces are represented by fourteen senators and eight senators from the tribal areas regardless of population, who serve staggered six-year terms.
The 1973 Constitution provides for a parliamentary form of Government with a bicameral legislature, comprising of the National Assembly and the Senate.
The membership of the Senate, which was originally 45, was raised to 63 in 1977 and to 87 in 1985. The membership of the Senate was again raised from 87 to 100 in 2002.
Since 2003, elections for Senate are being regularly held after every three years with half of the members of Upper House retiring and replaced by newly elected ones.
2003 Senate Elections
Elections to Senate are held in February 2003. Ruling party wins most seats and consolidates its power.
2006 senate elections
Senate elections were held in Pakistan on 6-10 March 2006. Half of the 100 seats in the Senate were up for election with the winning candidates serving six-year terms.
• Pakistan Muslim League (Q) 20 seats
• Muttahida Majlis-e-Amal 10 seats
• Independent 4 seats
• Pakistan People's Party
Parliamentarians 5 seats
• Mutahidda Qaumi Movement 3 seats
• Pakistan Muslim League (N) 1 seat
• Pakhtunkhwa Milli Awami Party 1 seat
• Pakistan Peoples Party 1 seat
• Awami National Party 1 seats
2009 Senate Elections Results
• Pakistan People's Party
Parliamentarians 27 seats
• Pakistan Muslim League (Q) 21 seats
• Independent 13 seats
• Muttahida Majlis-e-Amal 9 seats
• Pakistan Muslim League (N) 7 seats
• Awami National Party 6 seats
• Mutahidda Qaumi Movement 6 seats
• Jamiat Ulema-e-Islam (F) 4 seats
• Balochistan National Party 2 seats
• Jamhoori Wattan Party 1 seat
• National Peoples Party (Pakistan) 1 seat
• Pakhtunkhwa Milli Awami Party 1 seat
• Pakistan Muslim League (F) 1 seat
• Pakistan Peoples Party 1 seat
2012 Senate Elections Results
Pakistan Peoples Party 19 seats
Pakistan Muslim League (N) 8 seats
Awami National Party 7 seats
Pakistan Muslim League (Q) 4 seats
Mutahidda Qaumi Movement 4 seats
Jamiat Ulema-e-Islam 3 seats
Balochistan National Party (Awami) 2 seats
Pakistan Muslim League (F) 1 seat
Independent 5 seats
2015 Senate election results
Pakistan Muslim League (N) 16 seats,
Pakistan People’s Party (PPP) 7 seats
Pakistan Tehreek-e-Insaf 5 seats,
Muttahida Qaumi Movement (MQM) 4 seats
The National Party 3 seats
Pukhtunkhwa Milli Awami Party 3 seats
Balochistan National Party 1 seat
Jamiat Ulema-e-Islam (F) 1 seat
While an independent candidate also became senator from Balochistan.