The Constructors' titles for all classes were not recognized by the Federation following a political crisis with the constructors (represented by the International Permanent Bureau of Motorcycle Manufacturers) concerning the number of races to be held during the season and the abolition of the riders' championship.
† The 500 cc race was stopped by bad weather, and the FIM excluded the race from the World Championship.
†† The Sidecars and 125cc races were held on the 10.6-mile (17.364) km long Clypse Course other than the usual 37 mile (62 km) Snaefell mountain course.
Standings
Scoring system
Points were awarded to the top six finishers in each race. Only the four best races counted in the Sidecars, 125cc and 250cc, while in the 350cc and 500cc championships, the five best results were counted.