A young couple, David and Catherine Robinson, has to turn their large country house into a money-making proposition. Their solution is to invite the kids of the rich and famous to spend a summer enjoying all the loving care and attention they miss at home. After the youngsters arrive, David quickly realizes what the offensive little punks need is some real discipline, and so the summer begins.

With their headmistress under lock and key in her majesty's prison, the St Trinian's girls find themselves under the protection of the army. However, when the sixth form take a fancy to winning a trip to Italy through means fair or foul, the army discover this is one battle they can't win. Let loose in Europe, it is not long before St Trinian's have succeeded in endangering European relations.