Sid Carter (Sid James) is the cunning head of a criminal gang that includes the longhaired drip Ernie Bragg (Bernard Bresslaw), the cheeky Freddy (Bill Maynard) and Sid's honest son, Cyril (Kenneth Cope). Cyril does not want a life of crime, but is emotionally blackmailed by his father into going along with his scheme to rob Finisham Maternity Hospital for its stock of contraceptive pills and sell them abroad. Cyril reluctantly disguises himself as a new female nurse to case the hospital and the booty. Assumed to be one of the new student nurses who have just arrived, he is assigned to share a room with the shapely blonde nurse, Susan Ball (Barbara Windsor). Unfortunately for Cyril, he also catches the eye of the hospital lothario, Dr Prodd (Terry Scott).