MediaEntrantsGridGrand Prix
 
| Nr | Driver | Team | Car | Engine | Tyre | 
|---|---|---|---|---|---|
| 2 |  Juan Manuel Fangio | Automovil Club Argentino |  Ferrari 166 FL [013F] | Ferrari 166 FL V12C 2.0 | - | 
| 6 |  José Froilán González | Automovil Club Argentino |  Maserati 4CLT/48 [1599] | Maserati 4CL L4C 1.5 | - | 
| 10 |  Onofre Marimón | A. P. Pires |  Ferrari 125 [08C] | Ferrari 125 V12C 1.5 | - | 
| 12 |  Jorge Daponte | Automovil Club Argentino |  Maserati 4CLT/48 [1600] | Maserati 4CL L4C 1.5 | - | 
| 14 |  Alberto Crespo | A. Crespo |  Alfa Romeo 12C-37 [51204] | Alfa Romeo 12C L12C 4.5 | - | 
| 16 |  Chico Landi | Francisco Landi |  Ferrari 375 [005] | Ferrari 375 V12 4.5 | - | 
| 18 |  Francisco Marques | Francisco Landi |  Ferrari 125 [04C] | Ferrari 125 V12C 1.5 | - | 
| 20 |  Louis Rosier | Écurie (Louis) Rosier |  Ferrari 375 [375/51-02] | Ferrari 375 V12 4.5 | - | 
| 22 |  Robert Manzon | Équipe Gordini |  Simca Gordini T15 [12GC] | Gordini T18 L4 1.5 | - | 
| 24 |  André Simon | Équipe Gordini |  Simca Gordini T15 [11GC] | Gordini T18 L4 1.5 | - | 
| 26 |  Maurice Trintignant | Écurie (Louis) Rosier |  Talbot-Lago T26C [110001] | Talbot 23 CV L6 4.5 | - | 
| 28 |  Yves Giraud-Cabantous | Écurie (Louis) Rosier |  Talbot-Lago T26C-DA [110053] | Talbot 23 CV L6 4.5 | - | 
| 30 |  Nello Pagani | Officine Alfieri Maserati |  Maserati A6GCM [2032] | Maserati A6G L6 2.0 | - | 
| 32 |  Prince Bira | Ecurie Royale Siam |  Maserati 4CLT/48 [1607] | Osca 4500 V12 4.5 | - | 
| 34 |  Eitel Cantoni | E. Cantoni |  Maserati 4CL | Maserati 4CL L4C 1.5 | - | 
| 36 |  Danton Bazet | D. Bazet |  Maserati 4CL | Maserati 4CL L4C 1.5 | - | 
| 38 |  Asdrúbal Bayardo | A. Fontes |  Maserati 4CLT/48 [1608] | Maserati 4CL L4C 1.5 | - | 
| 40 |  Carlos Menditeguy | J. M. Fangio |  Alfa Romeo Tipo 308 [50017] | Alfa Romeo L8C 3.8 | - | 
| Pos | Nr | Driver | Car | Engine | Tyre | Time | Laps | 
|---|---|---|---|---|---|---|---|
| 1 | 2 |  Juan Manuel Fangio |  Ferrari 166 FL [013F] | Ferrari 166 FL V12C 2.0 | - | 01:17.400 | 0 | 
| 2 | 16 |  Chico Landi |  Ferrari 375 [005] | Ferrari 375 V12 4.5 | - | 01:20.200 | 0 | 
| 3 | 40 |  Carlos Menditeguy |  Alfa Romeo Tipo 308 [50017] | Alfa Romeo L8C 3.8 | - | 01:20.600 | 0 | 
| Official Name | 1º Gran Premio de Uruguay | 
|---|---|
| Circuit | Piriapolis | 
| Date | March 23 | 
| Pole | Juan Manuel Fangio 01:17.400 | 
| Fastest Lap | Juan Manuel Fangio 01:17.700 | 
| Podium | 1st Juan Manuel Fangio (65) , 2nd Chico Landi, 3rd Robert Manzon | 
| Prev race | Gran Premio di Siracusa March 16 | 
| Next race | Gran Premio de Montevideo March 30 | 
| P | N | Driver | Team | Car | Engine | Tyre | Time | Laps | FL | Led | Gr | Pts | 
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 2 |  Juan Manuel Fangio | Automovil Club Argentino |  Ferrari 166 FL [013F] | Ferrari 166 FL V12C 2.0 | - | 01:28:15.200 | 65 | 01:17.700 | 65 | 1 | 0 | 
| 2 | 16 |  Chico Landi | Francisco Landi |  Ferrari 375 [005] | Ferrari 375 V12 4.5 | - | 01:29:00.300 | 65 | 0 | 2 | 0 | |
| 3 | 22 |  Robert Manzon | Équipe Gordini |  Simca Gordini T15 [12GC] | Gordini T18 L4 1.5 | - | +1 lap | 64 | 0 | 0 | ||
| 4 | 40 |  Carlos Menditeguy | J. M. Fangio |  Alfa Romeo Tipo 308 [50017] | Alfa Romeo L8C 3.8 | - | +2 laps | 63 | 0 | 3 | 0 | |
| 5 | 24 |  André Simon | Équipe Gordini |  Simca Gordini T15 [11GC] | Gordini T18 L4 1.5 | - | +2 laps | 63 | 0 | 0 | ||
| 6 | 26 |  Maurice Trintignant | Écurie (Louis) Rosier |  Talbot-Lago T26C [110001] | Talbot 23 CV L6 4.5 | - | +3 laps | 62 | 0 | 0 | ||
| 7 | 18 |  Francisco Marques | Francisco Landi |  Ferrari 125 [04C] | Ferrari 125 V12C 1.5 | - | +3 laps | 62 | 0 | 0 | ||
| 8 | 12 |  Jorge Daponte | Automovil Club Argentino |  Maserati 4CLT/48 [1600] | Maserati 4CL L4C 1.5 | - | +5 laps | 60 | 0 | 0 | ||
| 9 | 30 |  Nello Pagani | Officine Alfieri Maserati |  Maserati A6GCM [2032] | Maserati A6G L6 2.0 | - | +7 laps | 58 | 0 | 0 | ||
| 10 | 20 |  Louis Rosier | Écurie (Louis) Rosier |  Ferrari 375 [375/51-02] | Ferrari 375 V12 4.5 | - | +8 laps | 57 | 0 | 0 | ||
| 11 | 38 |  Asdrúbal Bayardo | A. Fontes |  Maserati 4CLT/48 [1608] | Maserati 4CL L4C 1.5 | - | +9 laps | 56 | 0 | 0 | ||
| DNF | 34 |  Eitel Cantoni | E. Cantoni |  Maserati 4CL | Maserati 4CL L4C 1.5 | - | DNF | 42 | 0 | 0 | ||
| DNF | 36 |  Danton Bazet | D. Bazet |  Maserati 4CL | Maserati 4CL L4C 1.5 | - | DNF | 34 | 0 | 0 | ||
| DNF | 6 |  José Froilán González | Automovil Club Argentino |  Maserati 4CLT/48 [1599] | Maserati 4CL L4C 1.5 | - | DNF | 22 | 0 | 0 | ||
| DNF | 32 |  Prince Bira | Ecurie Royale Siam |  Maserati 4CLT/48 [1607] | Osca 4500 V12 4.5 | - | DNF | 6 | 0 | 0 | ||
| DNF | 28 |  Yves Giraud-Cabantous | Écurie (Louis) Rosier |  Talbot-Lago T26C-DA [110053] | Talbot 23 CV L6 4.5 | - | Engine | 0 | 0 | 0 | ||
| DNF | 14 |  Alberto Crespo | A. Crespo |  Alfa Romeo 12C-37 [51204] | Alfa Romeo 12C L12C 4.5 | - | DNF | 0 | 0 | 0 | ||
| DNS | 10 |  Onofre Marimón | A. P. Pires |  Ferrari 125 [08C] | Ferrari 125 V12C 1.5 | - | DNS | 0 | 0 | 0 |