The race was created in 1906 by Vincenzo Florio, a wealthy Sicilian pioneer motorist who had previously established the Coppa Florio race in Brescia in 1900. The first Targa Florio covered three laps of a 148-kilometre circuit winding through mountain roads, totalling around 444 kilometres, and was won by Alessandro Cagno in nine hours at an average of approximately 50 km/h. The severity of the terrain — some 2,000 corners per lap, over 1,100 metres of elevation change, and unpredictable mountain weather — made the event one of the most demanding in the world from its very first running.
By the early 1920s the course had been shortened to around 108 kilometres and the race had become one of Europe's most prestigious events, predating both the 24 Hours of Le Mans and the Mille Miglia. Mercedes scored important victories in the decade; Christian Werner's win in 1924 was particularly celebrated in Germany as the first by a non-Italian driver since 1920. In 1927 Czech driver Eliska Junkova became the first woman to compete in the race.
Over its seven decades the Targa Florio used several distinct circuit configurations. The original Grande course measured 148 kilometres and was used from 1906 to 1911 and again in 1931. A tour of the entire Sicilian coastline, measuring up to 1,080 kilometres per lap, was used for certain years between 1912 and 1950. The Medio course of approximately 108 kilometres served from 1919 to 1930, while the final and most familiar iteration — the Piccolo course of 72 kilometres — was in use from 1932 to 1936 and from 1951 to 1977.
The Piccolo course started and finished at Cerda and ran counter-clockwise. From Cerda the roads climbed through Collesano and Caltavuturo at altitudes exceeding 600 metres before dropping to sea level along the Buonfornello straight on the northern coast — a coastal straight longer than the Mulsanne Straight at Le Mans. Even the shortened 72-kilometre circuit contained around 800 to 900 corners per lap, and a single lap at road-car speeds took over an hour to complete. Learning the course properly demanded weeks of reconnaissance, and some manufacturers sent their drivers to study onboard film footage during the offseason. Porsche factory teams sometimes arrived three weeks early.
Lap speeds were consequently far lower than at any other round of the World Sportscar Championship. The outright lap record on the Piccolo circuit was set by Leo Kinnunen in 1970 driving a Porsche 908/3 at an average of just over 128 km/h, while Helmut Marko set the fastest-ever timed lap in 1972 in an Alfa Romeo 33TT3 at 33 minutes and 41 seconds. For comparison, Le Mans cars of the same era averaged in excess of 240 km/h.
The race returned to international prominence when the Carrera Panamericana was cancelled and its slot in the 1955 World Sportscar Championship was allocated to the Targa Florio. Mercedes-Benz arrived in force and the 300 SLR of Stirling Moss and Peter Collins won after more than nine hours of racing, with the Fangio and Karl Kling car second, a result that secured the manufacturers' championship for Mercedes over Ferrari and Maserati.
Porsche became the race's most successful constructor from 1956 onwards, developing cars specifically suited to the tight, twisty mountain circuit. The nimble Porsche 908/03 Spyder, derived from hillclimb machinery, proved far better adapted to the Piccolo course than the large, powerful prototypes that dominated at Le Mans and the Nurburgring.
The Targa held World Sportscar Championship status continuously from 1958 — when it replaced the discontinued Mille Miglia as the Italian round — through to 1973. Porsche won the majority of those championship rounds.
By the late 1960s and early 1970s, racing machinery had grown enormously powerful — Ferrari's 512S produced around 600 horsepower — while racing through small mountain villages at full speed with spectators standing at the roadside or even on the racing line. Marshalling across a 72-kilometre circuit was nearly impossible to maintain to any meaningful standard, and medical response times were catastrophic by modern measures. Brian Redman's 1971 accident illustrated the problem starkly: when his Porsche 908/03 hit a stone wall and caught fire after a steering failure, it took 45 minutes for any medical help to reach him; his Porsche teammates did not know his whereabouts for 12 hours.
The 1973 race proved to be the last under World Sportscar Championship regulations. During the event two fatal accidents occurred among competitors and spectators, and multiple serious injuries were sustained. The FIA subsequently mandated safety barriers at all sanctioned circuits from 1974, a requirement that was physically and financially impossible to fulfil along 72 kilometres of Sicilian public roads.
The race continued as a national event for four further years before a crash in 1977 — when bodywork failure sent a competitor off the road at speed on the Buonfornello straight, killing two spectators — prompted authorities to stop the race mid-running and end it permanently as a racing event.
The Targa Florio's influence on motorsport culture was profound. Porsche named the removable-hardtop variant of the 911 the Targa in direct honour of the race. The event has since been revived as the Targa Florio Rally, which forms part of the Italian Rally Championship. Its spirit has inspired similar road-rally events around the world, including Targa Tasmania (from 1992), Targa New Zealand (from 1995), and Targa Newfoundland (from 2002).
Despite its extreme dangers, over 71 years and 61 races using six different circuit configurations, the Targa Florio claimed nine lives including spectators — a relatively small toll compared with the Mille Miglia's 56 deaths over 30 years, attributed largely to the mountain roads' inherently low maximum speeds.