| «1991-03» | San Marino Grand Prix - XI Gran Premio di San Marino |
| 1991-04-28 | Imola - Autodromo Internazionale Enzo e Dino Ferrari - 61 laps × 5.04 km : 307.44 km |
| Pos | Grid | Car | Driver | Constructor | Laps | Time / Gap | Interval | Points |
|---|---|---|---|---|---|---|---|---|
| 1 | 1 | 1 | Ayrton Senna | McLaren • Honda | 61 | 1:35:14.750 | 193.671 km/h | 10 |
| 2 | 5 | 2 | Gerhard Berger | McLaren • Honda | 61 | +01.675 | +01.675 | 6 |
| 3 | 16 | 22 | JJ Lehto | Dallara • Judd | 60 | +1 lap | 4 | |
| 4 | 9 | 23 | Pierluigi Martini | Minardi • Ferrari | 59 | +2 laps | 3 | |
| 5 | 25 | 11 | Mika Hakkinen | Lotus • Judd | 58 | +3 laps | 2 | |
| 6 | 26 | 12 | Julian Bailey | Lotus • Judd | 58 | +3 laps | 1 | |
| 7 | 24 | 25 | Thierry Boutsen | Ligier • Lamborghini | 58 | +3 laps | ||
| 8 | 23 | 8 | Mark Blundell | Brabham • Yamaha | 58 | +3 laps | ||
| 9 | 21 | 35 | Eric van de Poele | Lamborghini | 57 | out of fuel | ||
| 10 | 19 | 26 | Erik Comas | Ligier • Lamborghini | 57 | +4 laps | ||
| 11 | 18 | 7 | Martin Brundle | Brabham • Yamaha | 57 | +4 laps | ||
| 12 | 15 | 15 | Mauricio Gugelmin | Leyton House • Ilmor | 55 | engine | ||
| 13 | 13 | 19 | Roberto Moreno | Benetton • Ford Cosworth | 54 | gearbox | ||
| 6 | 4 | Stefano Modena | Tyrrell • Honda | 41 | engine | |||
| 11 | 33 | Andrea de Cesaris | Jordan • Ford Cosworth | 37 | gearbox | |||
| 12 | 32 | Bertrand Gachot | Jordan • Ford Cosworth | 37 | suspension | |||
| 22 | 16 | Ivan Capelli | Leyton House • Ilmor | 24 | puncture | |||
| 17 | 29 | Eric Bernard | Lola • Ford Cosworth | 17 | engine | |||
| 2 | 6 | Riccardo Patrese | Williams • Renault | 17 | electronics | |||
| 10 | 3 | Satoru Nakajima | Tyrrell • Honda | 15 | accident | |||
| 8 | 24 | Gianni Morbidelli | Minardi • Ferrari | 10 | transmission | |||
| 7 | 28 | Jean Alesi | Ferrari | 2 | accident | |||
| 20 | 30 | Aguri Suzuki | Lola • Ford Cosworth | 2 | spin | |||
| 14 | 20 | Nelson Piquet | Benetton • Ford Cosworth | 1 | accident | |||
| 4 | 5 | Nigel Mansell | Williams • Renault | 0 | collision | |||
| DNS | 3 | 27 | Alain Prost | Ferrari | 0 | spin | ||
| DNQ | 17 | Gabriele Tarquini | AGS • Ford Cosworth | |||||
| DNQ | 18 | Fabrizio Barbazza | AGS • Ford Cosworth | |||||
| DNQ | 10 | Alex Caffi | Footwork • Porsche | |||||
| DNQ | 9 | Michele Alboreto | Footwork • Porsche | |||||
| DNP | 21 | Emanuele Pirro | Dallara • Judd | |||||
| DNP | 14 | Olivier Grouillard | Fondmetal • Ford Cosworth | |||||
| DNP | 34 | Nicola Larini | Lamborghini | |||||
| DNP | 31 | Pedro Chaves | Coloni • Ford Cosworth |
Fastest lap - 01:26.531 - 209.682 km/h - Gerhard Berger (lap 55)