All electors could vote for a political list and also cast a first preference vote for a specific candidate. The party with the highest number of list votes won the Senate seat, and the winning party's candidate with the highest number of first preference votes was declared elected.
Four electoral lists contested the North and Central American Senate division. The same lists also fielded candidates for the Chamber of Deputies and North and Central America.
The governing centre-left Democratic Party ran a united slate, as did Berlusconi's right-wing opposition list. The moderately conservative Union of the Centre (UDC), formerly aligned with Berlusconi, ran a separate list, as did a small coalition of right-wing and far-right parties called The Right–Tricolour Flame.
Marina Piazzi was born in Bologna on April 10, 1954, and moved to Mexico in 1976. She has taught Italian as a second language at the Istituto Italiano di Cultura in Mexico City and worked in the Italian department at the National Autonomous University of Mexico. Piazzi has been active for many years with the General Council for Italians Abroad and other Italian community organizations.
Massimo Seracini (June 7, 1943 – January 16, 2009) was born in Florence and received an economics degree from the University of Florence in 1962. He moved to the United States of America in the 1960s and worked in real estate in California. After his marriage failed, he returned to Florence and opened a bistro. He lived for extended periods in both countries during the last decades of his life and became a fixture of the Italian community in San Diego. Seracini had previously campaigned for an overseas seat in the Italian Chamber of Deputies in the 2006 general election as a candidate of the Union of Christian and Centre Democrats. A newspaper report from 2006 described him as "vague on details about his platform" but eager to serve Italians living in the diaspora. He died in San Diego in 2009, after a two-year battle with cancer.
Vittorio Coco is a broadcaster in Toronto, Ontario, Canada. He had previously sought election to the Italian Senate in 2006.
Berlusconi's electoral coalition won a narrow plurality, defeating the Democratic Party by only 793 votes. Basilio Giordano received the most votes of the candidates on Berlusconi's list and was declared elected.
Democratic Party incumbent Renato Turano actually received more first preference votes than Giordano, but, as his party list was defeated, he was not returned to office.
Note: The country-by-country totals provided by the Italian Ministry of the Interior do not entirely correspond with the final totals provided by the same source. Adding up the country-by-country totals yields the following results: People of Freedom 37,774; Democratic Party 36,734; Union of the Centre 7,087; The Right–Tricolour Flame 2,126. These results are the same as the provisional totals provided by La Repubblica with 120 out of 123 polling districts reporting. It is therefore assumed that the country-by-country totals represent the provisional and not the final totals.