Aspiring jazz musician Terence "Spike" Milligan reluctantly obeys his call-up and joins the Royal Artillery regiment at Bexhill-on-Sea, where he begins training to take part in World War II.

Jim Dale as Spike Milligan
Arthur Lowe as Major Drysdale
Bill Maynard as Sergeant Ellis
Tony Selby as Bill
Geoffrey Hughes as Larry
Jim Norton as Pongo
John Forgeham as Wally
Windsor Davies as Sergeant McKay
Spike Milligan as Leo Milligan (Spike's father)
Pat Coombs as Florence Milligan (Spike's mother)
Bob Todd as Bill Thompson, the Referee at the boxing bout
Gregory Phillips as Desmond Milligan (Spike's brother)
Alvar Liddell as himself (news broadcaster)
Robert Longden as Heavenly Bliss