16 August 1970 at Rhosnesni
| 500cc (Championship) | RH Sidecars (Championship) | 350cc (Championship) |
| 1- P. Collins | 1- T. Jones & T. Hall | 1- T. Williams |
| 2- P. Tyrer | 2- D.A. Jones & A. Jones | 2- J. Mann |
| 3- D. Evans | 3- R. Hall & E. Wynne | 3- K. Evans |
| RH Sidecars (3) | 250cc (Championship) | Duckhams Trophy |
| 1- T. Jones & T. Hall | 1- G. Drury | 1- T. Jones & T. Hall |
| 2- D.A. Jones & A. Jones | 2- P. Collins | 2- R. Hall & E. Wynne |
| 3- R. Hall & E. Wynne | 3- J. Cox | 3- D.A. Jones & A. Jones |
| Unlimited (2) | 250cc | Unlimited (1) |
| 1- P. Tyrer | 1- G. Drury | 1- P. Collins |
| 2- J. Cox | 2- J. Cox | 2- B. Forster |
| 3- T. Owen | 3- P. Tyrer | 3- G. Booth |
| Stevens Trophy | ||
| 1- E. Moseley | ||
| 2- T. Williams | ||
| 3- P. Williams |