9 July 1978 at Cross Houses
| 500cc | RH Sidecars | 350cc |
| 1- Terry Owen | 1- Steve Smith & Trevor Pye | 1- Mark Wadsworth |
| 2- Barry Robinson | 2- Pete Brown & John Morron | 2- Phil Alderman |
| 3- Gerry Hoole | 3- Trevor Jones & Paul Gollins | 3- Alec Lidgate |
| 250cc | ||
| 1- Mark Wadsworth | ||
| 2- Andy Challinor | ||
| 3- Rob Homer |