Having built a strong reputation in Formula Junior/Three, Formula Two and sports car racing Moser debuted in Formula One on 15 July 1967 at the British Grand Prix with a Vögele Team Cooper-ATS. Prior to this he had attempted to qualify for the German Grand Prix in 1966 with a Formula Two Brabham–Cosworth BT16, entered in his own name, but the engine failed in practice. He continued in 1968 with a Brabham-Repco BT20, in 1969 in a privately entered Brabham BT24 Cosworth, in 1970 with the Bellasi-Cosworth and again for one race in 1971. In total, he participated in 19 Formula One World Championship Grands Prix (12 starts), scoring a total of three championship points.