Arnaldo Carli started racing at age 16 and three years later attracted attention at the UVI Speed Grand Prix in Bologna, where his victory earned him selection for the 1920 Olympics. He formed part of the team pursuit quartet that took the gold medal at Antwerpen, but the Italian victory was controversial. In the semi-finals, the Italians faced South Africa. While enjoying a clear lead, the finishing pistol was fired for the South Africans with half-a-lap to go, and they slowed down. Despite a protest, the Italians went on to the final. One of their British opponents, Albert White, dropped from the group. The Italians assumed he was trying to interfere with their changeovers, and went wide to avoid him, while a French cyclist ran onto the track to punch White. The British won the race narrowly, but this time the Italians filed a protest, which was eventually upheld. Carli later turned professional, and twice competed in the Giro d’Italia (1926, 1931), although he did not finish either time. Between 1924 and 1929 Carli also competed in six-day races.