The fifth World Championship event within five weeks, the Belgian GP followed on the heels of the British, Monaco, Indianapolis and Swiss races and the toll was beginning to tell with only 14 cars arriving at Spa. These included the dominant Alfa Romeos of Giuseppe Farina, Juan Manuel Fangio and Luigi Fagioli. Ferrari was down to two 125s for Luigi Villoresi and Alberto Ascari - although Ascari had a new V12 engine to try out. The factory Talbot Lago team had three cars for Louis Rosier, Yves Giraud-Cabantous and Philippe Étançelin (standing in for the injured Eugène Martin). The rest of the field was made up of Talbot Lagos (notably one for Raymond Sommer), a single Alta and one Maserati for Antonio Branca.

Farina and Fangio were fastest as usual in practice with Fagioli unable to match them. Sommer split the Ferraris in his old Talbot Lago. The race would be a similar story. The Alfas went off on their own and Sommer battled with the two Ferraris. When the Alfa stopped for fuel Sommer found himself in the unlikely position of being race leader. Unfortunately his engine blew up. Ascari took the lead but he had to stop for fuel and that meant that the Alfas went ahead again with Fangio leading farina and Fagioli. Farina suffered transmission trouble in the closing laps and dropped to fourth behind the best of the surviving Talbot Lagos being driven by Rosier. Ascari finished fifth.