Jarno won many World and Italian kart titles and Benetton boss, Flavio Briatore paid for him to enter into German Formula Three midway through 1995, where he won the remaining two races of the season for the KMS team.

Continuing on the same way in 1996, he easily took the title. His Formula One debut came in 1997, when once again, Flavio Briatore stepped in. Tarso Marques, the driver for Minardi was to be replaced, and Jarno took the drive. Racing in Australia, he finished 9th after starting from 17th on the grid, but the season was hampered by mechanical failure, and lack of power.

Marques returned for the French Grand Prix, and Jarno moved to Prost, after Olivier Panis was injured at Montreal. He finished fourth in the German Grand prix, and shocked everyone by leading for more than half the race at Austria before his engine blew. He signed for Prost in 1998, and his best finish was sixth in Belgium.

The 99 season didn't see him fare much better although towards the end of the season there were some strong qualifying performances. Sadly, the engines' unreliability stopped him from proving what was so evident, that he had the talent, drive and passion that is necessary to succeed.

Eddie Jordan could see this and signed the young Italian to replace the retiring Damon Hill to partner Heinz-Harald Frentzen for the 2000 season. Here he put in some very strong drives, the only other driver that wasn't in a McLaren or a Ferrari to take a front row grid position throughout the entire year. However due to incidents involving other drivers or reliability problems with the EJ10,Jarno just couldn't manage to turn theses strong starts into point scoring finishes.

The 2001 championship produced a year of constant failures despite strong qualifying performances. Switching places with Giancarlo Fisichella at Renault for 2002, Jarno is hoping that he will finally get the opportunity to show the talent everyone knows he has. He finished the season with nine points overall, five behind teammate Jenson Button, the best results being fourth placed finishes in Monaco and Italy.

2003 sees Button leave the team and replaced by up and coming star Fernando Alonso. Together the duo should help Renault improve from their overall fourth placed finish in 2002.