Francis Bigger (Howerd) is a charlatan faith healer, convinced that "mind over matter" is more effective than medical treatment. During a lecture, he stumbles offstage and is admitted to the local hospital. In hospital, he incessantly groans and whines about being "maltreated", demanding better treatment than the other, eccentric patients. These include: bedridden layabout Charlie Roper (James) who shams illnesses to stay in hospital; Ken Biddle (Bresslaw) who makes frequent trips to the ladies' ward to flirt with his love interest, Mavis Winkle (Dilys Laye); and Mr Barron (Hawtrey) who seems to be suffering sympathy pains while his wife awaits the birth of their baby. While being treated, Bigger meets two very different doctors. Clumsy yet charming Dr Kilmore (Dale) is popular with the patients and loved from afar by the beautiful Nurse Clark (Harris) while hospital registrar Dr Tinkle (Kenneth Williams) is universally detested, as is his battleaxe Matron (Jacques), who harbours an unrequited love for him.