Larini began car racing in Formula Italia in 1983 before progressing to Formula Abarth in 1984, placing third in that series. He entered Italian Formula Three the same year and won the title in 1986, driving a Dallara for the Coloni team. He briefly contested Formula 3000 with Coloni in 1987.
Larini's rapid ascent brought a Formula One opportunity when Coloni entered the final two European rounds of the 1987 season. He failed to qualify at the Italian Grand Prix but started the Spanish Grand Prix before retiring. For 1988 and 1989, he joined the Osella team. Working with deeply uncompetitive equipment, Larini nonetheless drew notice for his commitment. His best result with Osella was ninth at the 1988 Monaco Grand Prix. In 1989 he ran sixth at the San Marino Grand Prix until a hub failure ended his race, and ran third at the Canadian Grand Prix before an electrical problem intervened.
The 1990 season brought a move to the well-funded Ligier team, but the car proved to be a consistent midfielder. Larini recorded a pair of seventh-place finishes and comfortably outperformed teammate Philippe Alliot. For 1991, he joined the new Modena team, again navigating the pre-qualifying system. He finished seventh in the season-opening United States Grand Prix but the team suffered acute financial difficulties and he qualified for only four further races before the team collapsed.
Out of a Formula One race seat in 1992, Larini was recruited by Ferrari to develop their active suspension system. He kept his race craft sharp by winning that year's Italian Touring Car Championship for Alfa Romeo and was called up to race-test the active suspension car at the end of the season, replacing Ivan Capelli. In 1993, he remained with Ferrari in a development role while again competing for Alfa Romeo in touring cars, winning the Deutsche Tourenwagen Meisterschaft.
In 1994, Larini gained another Ferrari race opportunity, this time substituting for the injured Jean Alesi. At the Pacific Grand Prix, he qualified seventh but was eliminated at the first corner alongside Ayrton Senna by Mika Häkkinen. At the San Marino Grand Prix, Larini took second place in deeply tragic circumstances — a result overshadowed entirely by the deaths of Roland Ratzenberger and Ayrton Senna across that terrible race weekend. It was the high-water mark of his Formula One career in competitive terms.
After further touring car work through 1995 and 1996 — including a third place in the German series in 1994, sixth in 1995, and eleventh in the ITC in 1996 — Larini's links to Ferrari helped him secure a seat at Sauber in 1997, as the Swiss team ran Ferrari-badged engines. He scored a point on his return at the Australian Grand Prix, but departed after five races following a series of disagreements with team principal Peter Sauber.
After leaving Formula One, Larini remained a fixture in touring car racing for Alfa Romeo in the European Touring Car Championship, then joined Chevrolet in the World Touring Car Championship from 2005 to 2009. He announced his retirement from professional driving on 21 November 2009, though he continued to race in amateur and historic events thereafter, including a 2017 debut in the NASCAR Whelen Euro Series at Franciacorta.
1986: Italian Formula 3 Champion (Dallara Alfa Romeo)
1992: Italian Superturismo Champion (Alfa Romeo 155 GTA turbo)
1993: Deutsche Tourenwagen Meisterschaft Champion (Alfa Romeo 155 V6 TI)