Moser was dominant from the mid-1970s to the early 1980s. He turned professional in 1973, showing a cultured pedaling style. But his powerful build meant he was not a gifted climber. He entered one edition of the Tour de France, in 1975, where he won two stages, held the Maillot Jaune for six days and finished 7th overall. He also won the 1977 world road racing championship in addition to collecting silver medals in 1976 and 1978. He won six times in three of the five monuments. Three editions of Paris-Roubaix, two victories in the Giro di Lombardia and one win in Milan-San Remo.