The 42° Targa Florio took place on 11 May, on the Circuito Piccolo delle Madonie, (Sicily, Italy). It was the third round of the 1958 World Sportscar Championship, which was running to new regulations introduced at the beginning of the season. The most influential of these regulations changes would be the 3.0 litre engine size limit. The event returned to the championship for the first time since 1955, following the demise of the Mille Miglia and the ban on road racing on mainland Italy. But such outcry did not deter Vincenzo Florio from holding his event on the traditional 45 mile mountainous circuit.