20 August 1978 at Sandford
| 500cc | RH Sidecars | 350cc |
| 1- Les Collins | 1- Trevor Jones & Paul Gollins | 1- Gerald Short |
| 2- Tom Leadbitter | 2- Pete Brown & John Morrow | 2- Clayton Williams |
| 3- Gerald Short | 3- Colin Jones & Willie Griffiths | 3- Rob Smith |
| 250cc | ||
| 1- Richard Wakeling | ||
| 2- Rob Smith | ||
| 3- Terry Rawlingson |