There was a five week break between the Spanish and Monaco Grands Prix which featured the International Trophy at Silverstone, which featured Formula 1 cars against the Chevrolet-engined Formula 5000 machines. Jackie Stewart (the winner in Spain) won the first heat but retired from the second when his throttle stuck open and he crashed at the first corner. This gave Graham Hill victory in his Brabham.

The Monaco organizers decided to allow 18 cars to start rather than the usual 16 and to do away with the complicated system of guaranteed places on the grid. It was simply a question of the fastest 18 cars and there were 23 present. Mario Andretti was unlucky as rain wiped out the Thursday qualifying and on Friday he suffered immediate mechanical trouble and so failed to qualify. Also out were the private March of Skip Barber, the factory March-Alfa Romeo of Nanni Galli and the factory March-Cosworth of Alex Soler-Roig and the third BRM of Howden Ganley (this being an old car).

At the front end of the grid Stewart was dominant, taking pole by 1.2secs from Jacky Ickx's Ferrari. The second row featured Jo Siffert's BRM and Chris Amon's Matra and the third row had Pedro Rodríguez (BRM) alongside Denny Hulme's McLaren. The top 10 was completed by Jean-Pierre Beltoise (Matra), Ronnie Peterson (March), Graham Hill (Brabham) and John Surtees (Surtees). Team Lotus had a terrible time with Reine Wisell 11th and Emerson Fittipaldi 17th. Amon had problems before the start so Ickx and Stewart were left to fight for the first corner with Siffert, who managed to slip ahead of the Ferrari and take second place behind Stewart. Monaco ace Graham Hill made a mistake on this occasion and crashed on the second lap and his Brabham teammate Tim Schenken hit a barrier two laps later while swerving to avoid François Cévert's Tyrrell when the Frenchman's engine cut. Both men got going again but Cévert crashed two laps later when the engine cut again. Stewart gradually increased his lead but the man making the most impact was Peterson who climbed up to second place in the mid-race, passing both Ickx and Siffert. Siffert later went out with an engine failure and so fourth place went to Hulme.