The field for the Belgian GP was much the same as it had been at Monaco a fortnight earlier although Dan Gurney had joined the series with a Climax-engined Eagle, his Weslake V12 engines still not being ready. The first new Lotus-BRM 43 appeared in the hands of Peter Arundell but Jim Clark stayed with his 2-liter Lotus-Climax form the previous year. Most of the teams had technical problems in practice and so John Surtees was fastest by three seconds in his Ferrari. Jochen Rindt was alongside in his Cooper-Maserati while Jackie Stewart finished off the front row in his V8-engined BRM, preferring to use the old engine rather than the new H16. The second row consisted on Jack Brabham's Brabham-Repco and Lorenzo Bandini in the second Ferrari while the third row featured Jo Bonnier's privately-entered Cooper-Maserati ahead of Mike Spence's Reg Parnell Racing Lotus and Richie Ginther in the second Factory Cooper-Maserati. Graham Hill (BRM) and Clark were alongside one another on the fourth row.

The weather was treacherous as the cars set off with Surtees taking the lead. At Burnenville the field ran into a heavy rain storm and Bonnier, Spence, Jo Siffert (Rob Walker Cooper) and Denny Hulme (Brabham-Repco) all went off. Rindt then had a huge spin in the Masta Kink but emerged without hitting anything but then Stewart, Hill and Bob Bondurant (in a private BRM) all lost control at the same place. Bondurant's car overturned but he escaped with only cuts and bruises. Hill's car was undamaged but he stopped to try and help Stewart, who was trapped in his upturned car, covered with petrol with a broken shoulder, a cracked rib and internal bruising. Fortunately he was rescued before the car caught fire but the Scotsman would be out of action for a couple of months.

With the accidents there were only seven cars left running with Surtees leading Brabham, Bandini, Ginther, Rindt, Ligier and Gurney. There was a battle for the lead in the early laps but then Rindt got ahead and stayed there with Surtees and Bandini chasing. As the track began to dry Rindt found his Cooper-Maserati to be a bit of a handful and slowed and on lap 24 Surtees went back into the lead. Bandini finished third a lap down, with Brabham fourth and Ginther fifth.