Yamamoto began his motorsport career in 1994 at the Suzuka Circuit Racing School in karting, where he was active until 2000. In 2001, the Japanese into formula racing and raced in the Japanese Formula 3 Championship for TOMs and immediately became fourth in the overall standings. He also competed in four races of the British Formula 3 Championship. In 2002, Yamamoto completely to Europe and drove in the German Formula 3 Championship for GM Motorsport and Team Kolles Racing, the team of Colin Kolles, for which he went to the start even at a race the Italian Formula 3 Championship. In both championships, he had no points. In 2003 he moved to the newly founded Formula 3 Euro Series, in which he took for Superfund TME, the team of Kolles. Without points, he finished the season 27th overall.
After two years in Europe Yamamoto returned in 2004 and went back to Japan again for TOMs in the Japanese Formula 3 Championship. He succeeded his first victory in Formula racing and he finished the season in seventh place overall. 2005 joined the Japanese to Kondo Racing in the Formula Nippon and was a podium placement tenth. He also drove in the Japanese Super GT, a Gran Turismo racing series, and finished with a win 13th overall. A highlight of the season Yamamoto was that he was allowed to drive the Grand Prix of Japan as the third pilot of Jordan, at the Kolles was now team leader, the free practice of Formula 1 weekend.
2006 Yamamoto began in Formula Nippon and Super GT. However, he left both series after three races in order for Super Aguri as third driver at four Grand Prix of Formula 1 2006 season to participate. From the Grand Prix of Germany, the Japanese took over the cockpit alongside Takuma by Franck Montagny Satō for the remaining seven races of the season. Only three race reached the finish. In his target arrivals Yamamoto could be precipitated only driver behind it. In the overall classification, he finished 26th place. For his commitment his sponsorship money were mainly responsible.
For 2007, Yamamoto lost his Super Aguri cockpit to the experienced Anthony Davidson, remained at first but as a test driver on board. In addition, he competed in the GP2 Series for the BCN team Competición the race to the first six race weekends. His greatest achievement was a ninth place in the feature race in Barcelona. Yamamoto did not score in the 2007 GP2 Series season. Starting the Hungarian Grand Prix Yamamoto moved surprisingly back into Formula 1, replacing the dismissed Albers at Spyker. He beat out well-known candidates like Christian Klien and Narain Karthikeyan, but less because of his driving skills as a result of financial contributions. His teammate at Spyker was the German Adrian Sutil, who was faster than Yamamoto in each qualifying. When Spyker Yamamoto worked again with Colin Kolles, who was his team boss already Formula 3 times together.
For the 2008 Formula 1 season Yamamoto was taken unexpectedly in February of Renault F1 test driver as a third under contract. However, his commitment focused more on demonstration runs and sponsors performances. During test runs, he was not used. In the middle of the GP2 Series 2008 season of the Japanese returned to the GP2 series. He was engaged by ART Grand Prix as a replacement for Luca Filippi. His teammate at ART was Romain Grosjean, who was just like Yamamoto test driver for Renault. His best result in 2008 was fourth in the sprint race at the Hungaroring. It was also the first time that Yamamoto generated outside Japan points in a racing series. Yamamoto finished with three points 23rd place overall. For ART he has brought fewer points than its predecessor Filippi.
In the 2008/2009 GP2 Asia Series season Yamamoto stayed with ART Grand Prix. With a good start to the season in Shanghai, the Japanese took third in his first podium placement in the GP2 series. At the end of the season Yamamoto finished ninth in the overall standings. His best overall placement in a GP2 series, however, was asked by his team- mate Nico Hülkenberg and Pastor Maldonado, who shared a flight deck, in the shade.
After his involvement in the GP2 Asia Series Yamamoto returned to the Formula racing in 2009 and moved to the back of the ADAC GT Masters. Starting for Team Rosberg, he finished at the end of the season the 32nd overall. 2010, the Japanese returned surprisingly back into Formula 1, and was test driver after three Grand Prix of the new team HRT. In HRT, he worked again with Colin Kolles and should first participate in some Grand Prix on Friday workout. At the Turkish Grand Prix he took over for the first time this position. At the Grand Prix of Great Britain, the Japanese went as a substitute for Bruno Senna, who was suspended for this race at the start. From the next race, the Grand Prix of Germany, Yamamoto stood as a substitute for Karun Chandhok to race. When the Singapore Grand Prix, he had his cockpit for an alleged food poisoning at Klien, the test and reserve driver for the team, assign. As it turned out a short time later, the real reason for the suspension was not food poisoning, but financial difficulties. The money from Yamamoto's mother, who financed the cockpit her son, was not arrived on time at HRT. After two more races in the cockpit was replaced Yamamoto for the Grand Prix of Brazil by Klien. At the end of the season was taken by the Japanese, who had participated in seven races as in 2006 and 2007, the 26th place in the Drivers' World Championship.
In 2011, Yamamoto for the first three Grand Prix test and reserve driver position at a Virgin.
Yamamoto was able in his Formula 1 career no points retract.
- 2006: Formula 1 ( 26th place ); Formula Nippon ( 11th place ); Super GT ( # 21 )
- 2007: Formula 1 ( 24th place ); GP2 Series (No. 30)
- 2008: GP2 Series (No. 23); Formula 1 ( test driver )
- 2009: GP2 Asia Series (No. 9); ADAC GT Masters ( # 32 )
- 2010: Formula 1 ( # 26 )
- 2011: Formula 1 ( test driver )