It was a development of the team's 641 chassis, which had mounted a championship challenge in 1990.
Ferrari started the 1991 season with high hopes of winning the championship.
Jean Alesi signed a contract with the Scuderia when Nigel Mansell returned to the Williams team.
The 642's best result was a second-place taken by Alain Prost at the 1991 United States Grand Prix, held at the Phoenix street circuit.
(key) (results in italics indicate fastest lap) * 39.5 points scored using Ferrari 643