Alessandro Cagno started racing in 1902, at the age of eighteen. He came second on the Belgian circuit of Ardennes. In 1904 he won the hillclimb at Susa - Mont Cenis and he finished third at the Mont Ventoux hillclimb in 1905 driving a Gordon Bennett.
In 1906 he took part at the first running of the Targa Florio winning the race while driving a Fab Auto Itala SA in nine hours, averaging 30 miles per hour (50 km/h).
Cagno was also a flying enthusiast, and he designed and tested aircraft, founding Italy's first flying school in Pordenone. He volunteered to fight in the war in Libya, and built the first bomber aircraft.
Cagno drove the Itala built for the 1908 France Grand Prix at Dieppe. The race was over 10 laps of a 48 mile course. He finished 11th out of 47 starters. The Itala also competed in the USA in 1908.
In 1912, Cagno returned to Fiat as Chief Tester of racing cars and General motor vehicle Tester. During the war he ran the General Testing Office for the Italian and French armies. After the war he returned to racing and concluded his career in 1923, leading the Fiat team to victory in the Leningrad-Tiblisi-Moscow race.
He continued to work with Fiat as a test driver and dealer.