| «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 | Q1 | Q2 | Best | Gap | Interval |
|---|---|---|---|---|---|---|---|---|---|
| 1 | 1 | 1 | Ayrton Senna | McLaren • Honda | 01:21.877 | 01:43.633 | 01:21.877 | 221.601 km/h | |
| 2 | 2 | 6 | Riccardo Patrese | Williams • Renault | 01:21.957 | 01:42.455 | 01:21.957 | +00.080 (+0.098%) | +00.080 |
| 3 | 3 | 27 | Alain Prost | Ferrari | 01:22.195 | 01:42.429 | 01:22.195 | +00.318 (+0.388%) | +00.238 |
| 4 | 4 | 5 | Nigel Mansell | Williams • Renault | 01:22.366 | 01:41.878 | 01:22.366 | +00.489 (+0.597%) | +00.171 |
| 5 | 5 | 2 | Gerhard Berger | McLaren • Honda | 01:22.567 | 01:40.322 | 01:22.567 | +00.690 (+0.843%) | +00.201 |
| 6 | 6 | 4 | Stefano Modena | Tyrrell • Honda | 01:23.511 | 01:44.613 | 01:23.511 | +01.634 (+1.996%) | +00.944 |
| 7 | 7 | 28 | Jean Alesi | Ferrari | 01:23.945 | 01:41.149 | 01:23.945 | +02.068 (+2.526%) | +00.434 |
| 8 | 8 | 24 | Gianni Morbidelli | Minardi • Ferrari | 01:24.762 | 01:24.762 | +02.885 (+3.524%) | +00.817 | |
| 9 | 9 | 23 | Pierluigi Martini | Minardi • Ferrari | 01:24.807 | 01:24.807 | +02.930 (+3.579%) | +00.045 | |
| 10 | 10 | 3 | Satoru Nakajima | Tyrrell • Honda | 01:25.345 | 01:42.063 | 01:25.345 | +03.468 (+4.236%) | +00.538 |
| 11 | 11 | 33 | Andrea de Cesaris | Jordan • Ford Cosworth | 01:25.491 | 01:44.118 | 01:25.491 | +03.614 (+4.414%) | +00.146 |
| 12 | 12 | 32 | Bertrand Gachot | Jordan • Ford Cosworth | 01:25.531 | 01:44.897 | 01:25.531 | +03.654 (+4.463%) | +00.040 |
| 13 | 13 | 19 | Roberto Moreno | Benetton • Ford Cosworth | 01:25.655 | 01:45.216 | 01:25.655 | +03.778 (+4.614%) | +00.124 |
| 14 | 14 | 20 | Nelson Piquet | Benetton • Ford Cosworth | 01:25.809 | 01:42.911 | 01:25.809 | +03.932 (+4.802%) | +00.154 |
| 15 | 15 | 15 | Mauricio Gugelmin | Leyton House • Ilmor | 01:25.841 | 01:25.841 | +03.964 (+4.841%) | +00.032 | |
| 16 | 16 | 22 | JJ Lehto | Dallara • Judd | 01:25.974 | 01:43.397 | 01:25.974 | +04.097 (+5.004%) | +00.133 |
| 17 | 17 | 29 | Eric Bernard | Lola • Ford Cosworth | 01:25.983 | 01:25.983 | +04.106 (+5.015%) | +00.009 | |
| 18 | 18 | 7 | Martin Brundle | Brabham • Yamaha | 01:26.055 | 01:26.055 | +04.178 (+5.103%) | +00.072 | |
| 19 | 19 | 26 | Erik Comas | Ligier • Lamborghini | 01:26.207 | 01:46.667 | 01:26.207 | +04.330 (+5.288%) | +00.152 |
| 20 | 20 | 30 | Aguri Suzuki | Lola • Ford Cosworth | 01:26.356 | 01:26.356 | +04.479 (+5.470%) | +00.149 | |
| 21 | 21 | 35 | Eric van de Poele | Lamborghini | 01:26.550 | 01:47.619 | 01:26.550 | +04.673 (+5.707%) | +00.194 |
| 22 | 22 | 16 | Ivan Capelli | Leyton House • Ilmor | 01:26.602 | 01:52.949 | 01:26.602 | +04.725 (+5.771%) | +00.052 |
| 23 | 23 | 8 | Mark Blundell | Brabham • Yamaha | 01:26.778 | 01:49.539 | 01:26.778 | +04.901 (+5.986%) | +00.176 |
| 24 | 24 | 25 | Thierry Boutsen | Ligier • Lamborghini | 01:26.998 | 01:44.125 | 01:26.998 | +05.121 (+6.255%) | +00.220 |
| 25 | 25 | 11 | Mika Hakkinen | Lotus • Judd | 01:27.324 | 01:47.444 | 01:27.324 | +05.447 (+6.653%) | +00.326 |
| 26 | 26 | 12 | Julian Bailey | Lotus • Judd | 01:27.976 | 01:45.931 | 01:27.976 | +06.099 (+7.449%) | +00.652 |
| 27 | 17 | Gabriele Tarquini | AGS • Ford Cosworth | 01:28.175 | 01:28.175 | +06.298 (+7.692%) | +00.199 | ||
| 28 | 18 | Fabrizio Barbazza | AGS • Ford Cosworth | 01:29.665 | 01:29.665 | +07.788 (+9.512%) | +01.490 | ||
| 29 | 10 | Alex Caffi | Footwork • Porsche | 01:30.280 | 02:06.589 | 01:30.280 | +08.403 (+10.263%) | +00.615 | |
| 30 | 9 | Michele Alboreto | Footwork • Porsche | 01:30.762 | 09:39.741 | 01:30.762 | +08.885 (+10.852%) | +00.482 | |
| 31 | 21 | Emanuele Pirro | Dallara • Judd | 01:26.305 | 01:26.305 | +04.428 (+5.408%) | |||
| 32 | 14 | Olivier Grouillard | Fondmetal • Ford Cosworth | 01:26.789 | 01:26.789 | +04.912 (+5.999%) | +00.484 | ||
| 33 | 34 | Nicola Larini | Lamborghini | 01:26.886 | 01:26.886 | +05.009 (+6.118%) | +00.097 | ||
| 34 | 31 | Pedro Chaves | Coloni • Ford Cosworth | 01:31.239 | 01:31.239 | +09.362 (+11.434%) | +04.353 |