25 September 1988 at St. Erme
| 500cc | RH Sidecar Open (One) | Solo Open |
| 1- Mark Simmonds | 1- Nick Fumarola & Derek Thomas | 1- Gary Lobb |
| 2- Wayne Barrett | 2- Dave Westaway & Alan Borlase | 2- Mark Simmonds |
| 3- Jonathan Orchard | 3- Stuary Rattenbury & Chris Carter | 3- Wayne Barrett |
| Invitation | RH Sidecar Open (Two) | 350cc |
| 1- David Plain | 1- Dave Westaway & Alan Borlase | 1- Paul Jeffrey |
| 2- Steve Jacobs | 2- Nick Fumarola & Derek Thomas | 2- Gary Hendrickson |
| 3- Clive Stoneman | 3- Terry Phillips & Kevin Williams | 3- Mike Bowden |
| 250cc | Sidecar Juniors | Juniors |
| 1- Mark Simmonds | 1- Stuary Rattenbury & Chris Carter1 | 1- Gary Hendrickson |
| 2- Paul Jeffrey | 2- Ian Walkley & Gary Marchment | 2- Steve Jacobs |
| 3- Mike Bowden | 3- Derek Fox & Joe Sturtridge | 3- David Plain |
| Intermediates | Juniors | Cadets |
| 1- Jonathan Geraghty | 1- Darren Ella | 1- Marcus Hancock |
| 2- Chris Davey | 2- Roger Lobb | 2- Joanne Ella |
| 3- Mike Bowden | 3- Peter Davy | 3- Jonathan Ella |
| Senior A | ||
| 1- Mark Rowe | ||
| 2- Jason Prynne |
15 May 1988 at St. Erme
| 500cc | Expert | 350cc |
| 1- Mark Simmonds | 1- Wayne Barrett | 1- Mike Bowden |
| 2- Wayne Barrett | 2- Mark Simmonds | 2- Adrian Kessell |
| 3- Simon Gittings | 3- Jock Davidson | 3- Andrew Holliman |
| Open | First RH Sidecars Open | 250cc |
| 1- Wayne Barrett | 1- Dave Westaway & Alan Borlase | 1- Mark Simmonds |
| 2- Mark Simmonds | 2- Ken Hicks & Colin Hicks | 2- Dave Bleaken |
| 3- Simon Gittings | 3- Gerry Wheeler & Stuart Rattenbury | 3- Mike Bowden |
| Juniors | Second RH Sidecars Open | Invitation |
| 1- Darren Matthews | 1- Dave Westaway & Alan Borlase | 1- Mark Wells |
| 2- Gary Hendrikson | 2- Gerry Wheeler & Stuart Rattenbury | 2- Bill Cook |
| 3- Mark Wells | 3- Ian Walkley & Gary Marchant | 3- Steve Jacobs |
| Junior Sidecars | ||
| 1- Henry Dingle & Paul Jasper | ||
| 2- Mark Quintrell & Shane Gregor |