Moser made his name in F3 in the mid-1960s. He made his Grand Prix debut in 1967 in a Cooper-ATS. He finished 5th in a Brabham-Repco at Zandvoort in 1968. He died in 1974 after sustaining fatal head injuries when he crashed heavily in the Monza 1,000km race as he toured back to the pits without refastening his safety harness.
Silvio Moser started racing in 1961 with a Volvo and a Jaguar XK120, taking a number of class wins mainly in hillclimbs though he did finish second overalll and first in class in the Coupe Paris at Monthléry in the Volvo.
In 1962 he aquired a Lotus 20 Formula Junior which he took hillclimbing as circuit racing was banned in Switzerland following the tragedy at Le Mans in 1955.
He continued with Lotus through 1963 but later in the year Charles Vögele funded a BT6 Brabham FJ. It was in this car that Moser convincingly won the Argentine Temporada series at the start of the 1964 season. He continued with it for the rest of the year with some success, taking a win at Garda and second in the F3 race at Monaco behind Jackie Stewart.
He raced an Alfa Romeo Giulia TZ in the Coppa Inter-Europa at Monza that year finishing 5th overall and first in class and another class win with the car in the 1000 km de Paris at Montlhéry with fellow Swiss driver, Karl Foitek.
Moser then moved into Formula 2 in 1965 with his own team but continued to race in F3 where he was more competitive, winning races at Syracuse, La Chatre and Rosario.
In 1966 he went to Argentina at the start of the year, taing a win at Rosario. A number of F2 class win followed in hillclimbs but circuit results were thin on the ground.
He made his debut in F.1 in 1967 at the wheel of an aged Cooper T81 fitted with a 2.7-litre ATS engine, finishing 6th overall in the non-championship Grnad Prix at Siracusa and retiring from teh british Grand Prix at Silverstone.
After his success with his personal Alfa Romeo TZ, Moser drove a works Alfa Romeo GTA at the Circuito del Mugello, finishing 7th overall and 1st of class with Italian co-driver 'Hoga'. He also practiced a 2-litre Alfa Romeo 33 for Alfa Romeo Switzerland at the Ollon-Villars hillclimb but did not take part as the car was not ready following an engine change.
In September Silvio, along with team-mates Clay Regazzoni and Jürg Dubler, won the F3 Championship for Nations for Switzerland at Hockenheim driving a Tecno.
In 1968 he then went into F1 full-time with Charles Vögele's ex-Guy Ligie Brabham BT20-Repco re-painted red, scoring an incredible 5th in pouring rain at Zandvoort in the Dutch Grand Prix.
He took sixth at Watkins Glen in 1969 but then embarked on a disastrous season in 1970 with the hopeless Bellasi-Ford, which effectively put an end to his immediate Grand Prix career.
Returning to Formula 2, he drove a Brabham in 1971 and 1972, taking second at the Monza Lottery GP, but had a thin time of it with a Surtees in 1973.
Moser was planning to race a March in Formula 2 in 1974, as well as making a return to Grands Prix with a Bretscher Brabham, but in the Monza 1000 Km, he sustained fatal head injuries when he crashed heavily as he toured round to the pits in his Lola T292 sports car, having failed to refasten his harness after an incident out on the circuit. Despite several operations, poor Moser died in hospital the following month without regaining consciousness.