Frankie Howerd makes the first of his two appearances in the film series and stars alongside regulars Sid James, Kenneth Williams, Jim Dale, Charles Hawtrey, Joan Sims, Peter Butterworth, and Bernard Bresslaw.

Charlatan faith healer Francis Bigger, who convinces attendees, with the help of his assistant Chloe Gibson, that "mind over matter" is more effective than medical treatment, suffers an accident during one of his lectures.

Admitted to the local hospital, he quickly demands a private room after encountering his ward's eccentric patients: bedridden layabout Charlie Roper, who fakes symptoms to stay in hospital; Ken Biddle who, while recovering from an operation, makes frequent trips to the ladies' ward to flirt with his love interest, Mavis Winkle; and Mr Barron, whose mental health has declined following news his wife is due to give birth to their first child, leaving him suffering sympathy pains.

During Bigger's stay in hospital, he meets the clumsy yet charming Dr. Jim Kilmore, who is popular with the patients and loved from afar by the beautiful Nurse Clarke, who subsequently causes him trouble by accident while being checked over.

Shortly after Bigger's arrival, the hospital receives a novice nurse, Sandra May, who reveals to Clarke that she intends to meet Tinkle to repay him for saving her life - although in reality, she was merely given treatment for tonsillitis.

After completing a shift on the wards, May heads for Tinkle's room to profess her love for him, violating hospital rules that female staff are not permitted in the male quarters.