Only eight days after the first World Championship event at Silverstone the teams were in action again at Monaco with Alfa Romeo facing a rather more difficult task than in Britain thanks to the appearance of the Ferrari team with its 125s being driven by Luigi Villoresi, Alberto Ascari and Raymond Sommer. Alfa Romeo has three 158s for Giuseppe Farinia, Juan Manuel Fangio and Luigi Fagioli. A fourth car was entered by Peter Whitehead but a series of engine problems meant that he did not qualify. The rest of the field was made up of Talbot Lagos and Maseratis although Harry Schell entered a tiny JAP-engined Cooper and there were a pair of Equipe Gordini Simca-Gordinis for drivers Maurice Trintignant and Robert Manzon.

Sunday was windy which caused some curious conditions at Tabac Corner where spray from the harbor made the track surface rather damp and on the first lap Farina - who was running second to Fangio - lost control and hit by the Maserati of José Froilán González (which had qualified third). Fagioli swerved to a halt and Louis Rosier managed to stop his Talbot Lago before hitting the Alfa only to have the car punted into Fagioli's 158 when it was hit by Manzon. Schell, Baron Emmanuel de Graffenried and Franco Rol (Maseratis), Cuth Harrison (ERA) and Trintignant were all involved. Nine cars were eliminated immediately and González's car retired on the next lap as a result of damage from the crash.

Fangio managed to get through the wreckage at the end of the lap but Villoresi stalled as he slowed down and so it was Ascari who emerged in second place. Villoresi dropped right to the back of the field and provided the excitement as he charged back to take second place only to retire with an axle problem. Fangio finished a lap ahead of Ascari with Chiron a further lap down in third.