Alfieri was the fourth son of Rodolfo Maserati, a railway engine driver. The Maserati family produced six brothers involved in motoring and racing: Carlo, Bindo, Alfieri, Mario, Ettore, and Ernesto. Carlo was the eldest and an early pioneer; it was Carlo who first introduced Alfieri to motorcycles and automobile racing. After Carlo's death in 1910, Alfieri became the organising force among the brothers.
Alfieri began his competition career in 1908, entering the Grand Prix des Voiturettes at Dieppe. He subsequently raced Bianchi and Isotta Fraschini machinery in Voiturette events in the years before the First World War, and also worked as a commercial agent for Isotta Fraschini.
In 1912, Alfieri and Ettore travelled to Argentina on a mission for Isotta Fraschini. Back in Italy by 1914, the brothers established a motor repair shop and small workshop in Bologna.
On 14 December 1914, Alfieri registered the Societa Anonima Officine Alfieri Maserati at the Bologna Chamber of Commerce. Both Alfieri and Ettore served in the First World War; during their absence, brother Ernesto ran the workshop. After the armistice, a larger production plant was established in Bologna, and the enterprise turned toward competition preparation and the building of original racing machinery. Bindo joined the company in 1920, Ettore in 1921, and Ernesto — who became the company's chief test driver — in 1927.
The distinctive trident badge was designed by Mario Maserati, who was a painter rather than an engineer or driver, drawn from the Fountain of Neptune in Bologna's Piazza Maggiore.
Alfieri was a consistently successful competition driver throughout the 1920s. He won the Coppa della Velocità at Brescia in 1921. In hillclimb events he was especially dominant: he won the Susa-Moncenisio climb three times — in 1921, 1922, and 1923 — and the Aosta-Gran San Bernardo in both 1922 and 1923. He also won the Circuito del Mugello road race in 1922. Between 1922 and 1926 he also served as head mechanic for Diatto.
In 1926 Alfieri designed and built the Tipo 26, Maserati's first car produced entirely in-house. He drove the Tipo 26 himself on its competition debut at the Targa Florio, winning the 1500 cc class outright. The Tipo 26B followed with a supercharged straight-eight engine producing around 120 bhp. Alfieri continued to race Tipo 26 variants in major Italian events through the late 1920s.
A more ambitious project was the Tipo V4, a 16-cylinder car formed by mating two supercharged straight-eight engines on a common crankcase. The Tipo V4 competed at the Gran Premio di Monza and set a world speed record.
In 1927, Alfieri entered the 1st Coppa Messina, a road race of 312 km on the Circuit of Monti Peloritani in Sicily. On the first lap he lost control, and his Tipo 26 overturned after striking a ditch. He suffered grave injuries; emergency surgery removed one kidney, which was found to be irreparably damaged. Although he returned to racing subsequently — his last recorded competition appearance was the 1930 Gran Premio delle Vetturette — he never recovered full health, and the loss of the kidney left him chronically weakened.
In early 1932, Alfieri underwent surgery in Bologna related to his remaining kidney. He died from a kidney infection in the aftermath of the operation, on 3 March 1932, at the Ospedale Maggiore in Bologna. He was 44 years old.
Alfieri died four years before the Maserati company was sold to the industrialist Adolfo Orsi, who moved production from Bologna to Modena in 1940. Brothers Ernesto and Bindo continued with Maserati until 1947, when their contractual obligations to Orsi expired; they then co-founded OSCA (Officine Specializzate Costruzione Automobili). Alfieri's name was revived by Maserati in 2014 when the company presented the Maserati Alfieri concept car to mark the centenary of the company's founding.