The Senate is elected every five years by universal suffrage. All Italians aged 25 and above are entitled to vote. Any voter of 40 years of age or over can be elected.

The Senate consists of 315 elected members, plus a number of appointed life senators and ex officio life senators. Among the life senators appointed by the President of the Republic "for outstanding merits in social, scientific, artistic and literary fields", we can recall such names as orchestra conductor Arturo Toscanini (who rejected the appointment), poet Eugenio Montale and playwright Eduardo De Filippo, to mention but a few. Former Presidents of the Republic are ex officio life senators. Presently the senators appointed for life by the President of the Republic are: Mario Monti, Elena Cattaneo, Renzo Piano, Carlo Rubbia and Liliana Segre. The former President of the Republic currently sitting in the Senate is Giorgio Napolitano.

The 315 elective seats of the Senate are distributed among the twenty Italian regions in proportion to their population, save for the seats assigned to the Overseas constituency. One seat is assigned to Valle d'Aosta, two to Molise and at least seven seats to each of the other eighteen regions.

Under Article 58 of the Italian Constitution, any voter of 40 years of age or over can be elected. He or she may be proposed to stand for election by political parties, political groups or individual citizens. The candidates compete for the attribution of a seat in a single-member constituency. Those candidates who form associations between themselves compete on a group basis and thus also for the seats assigned on a proportional basis. The symbols and names of lists are filed with the Ministry of the Interior. Later, the names of the candidates standing for a seat are also filed therewith.

The Senate is elected on a proportional representation basis. Polls take place during two consecutive days. A voter may cast only one vote. If a seat becomes vacant during a parliamentary term, the candidate with the second highest number of votes from the list of the former senator will accede to the seat.