He started his career in rallying in 1972 and turned to circuit racing in 1975 with the Italian Renault 5 Cup. By 1980 he had become a top Formula 3 driver, winning the Monaco F3 Grand Prix and the 1981 European Formula 3 Championship with eight victories. In 1982 he signed to drive for Arrows before moving to Alfa Romeo in 1983, scoring a fifth place in Zandvoort. When Benetton became Alfa Romeo's team sponsor in 1984, Baldi lost his drive, and joined the underfunded Spirit team until 1985.
After retiring from Formula One he went to enjoy a successful carrer in sports car racing, driving for the works Martini-Lancia team in 1984 and 1985. In 1986, he switched to a Porsche 956 from Richard Lloyd Racing's outfit, returning to a works drive in 1988 with the Sauber-Mercedes team, with whom Baldi won the 1990 World Sportscar Championship, sharing the car with Jean-Louis Schlesser. In 1991 and 1992 he was a driver for Peugeot. He had a brief return to F1, doing most of the test driving for the Modena Lambo project.
