The race was the first of three international events in Buenos Aires across two weeks. The 1955 1000 km Buenos Aires opened the sports car World Championship season, and a Formula Libre race at the end of January saw another appearance from the same machinery.
Twenty-one cars represented five constructors: Mercedes-Benz fielded four cars for Juan Manuel Fangio, Karl Kling, Stirling Moss, and Hans Herrmann. Scuderia Ferrari brought four drivers — José Froilán González, Nino Farina, Maurice Trintignant, and Umberto Maglioli — across three cars. Officine Alfieri Maserati entered six cars, including drivers Jean Behra, Roberto Mieres, Luigi Musso, Carlos Menditeguy, Sergio Mantovani, and Clemar Bucci. Scuderia Lancia entered three Lancia D50s for Alberto Ascari, Luigi Villoresi, and Eugenio Castellotti. Equipe Gordini entered three cars.
González put his Ferrari No. 12 on pole position with a time of 1:43.1. Ascari in the Lancia D50 qualified second at 1:43.6. Fangio's Mercedes was third at 1:43.7. Jean Behra's Maserati was fourth at 1:43.8. Farina qualified fifth at 1:43.9. The four Mercedes drivers were spread from third to tenth positions on the grid.
The race was conducted in very hot and dry conditions that proved severely taxing for both drivers and machinery. Five cars retired within the first two laps, exposing the attrition that would define the afternoon. None of the three Lancias and none of the three Gordinis reached the midpoint of the race. Of the twenty-one starters, only seven were classified at the finish.
Fangio, who was 43 years old at the time and a native Argentine, had prepared deliberately for the conditions. According to accounts from the period, he moved to Argentina a month before the race and reduced his daily water consumption to one litre to acclimatise himself to the extreme summer heat. His preparation paid off: Fangio and Roberto Mieres of Maserati were the only two drivers who completed all 96 laps without handing their cars to a relief driver, either from exhaustion or in response to their team-mates' retirements.
Fangio won from his third grid position, driving continuously throughout the three-hour event. He posted the fastest lap of the race, a 1:48.3, set on lap 45. The victory came at a physical cost: his leg rubbed against the chassis frame for the full duration of the race, the frame being heated by the exhaust pipe. The burns left a permanent scar. Recovery from the injury took approximately three months; during that period Fangio finished second in the 1955 Mille Miglia. The next Formula One round, the Monaco Grand Prix, was not held until late May.
The intensity of the heat forced widespread car-sharing between drivers, making the final classification unusual. Ferrari achieved two podium finishes through three-way arrangements.
The No. 12 Ferrari, which González had placed on pole, finished second. González drove a substantial portion of the race before handing over to Farina, who in turn shared with Trintignant. The same three drivers also contributed to the third-placed result from the No. 10 Ferrari, entered for Farina and Maglioli, creating a complex interlocking classification in which drivers appeared across multiple finishing positions.
At Mercedes, both Moss in No. 6 and Kling in No. 4 retired their own cars during the race. The two then joined Herrmann in the No. 8 car and the shared effort was classified fourth. Of the Maserati entries, only Mieres — who drove unshared — and two further cars completed the race.
The result opened the 1955 World Championship with Fangio leading the standings. Two weeks later he and Mercedes also won the 1955 Buenos Aires Grand Prix Formula Libre race, though that event carried no championship points. The 1955 season would go on to be won by Fangio, who took the title with victories at Monaco, Belgium, the Netherlands, and Italy in addition to the Buenos Aires opener.