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. The day after his admission, Bigger meets Dr. Kenneth Tinkle, Kilmore's superior, who is detested by the patients as much as is the battleaxe Matron, who harbors an unrequited love for Tinkle.




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. However, Tinkle cruelly rebuffs her affection, only to find himself caught in an awkward situation by Kilmore and Matron. Fearing for his position, after the departure of May and Kilmore, Tinkle contrives with Lavinna to cover up the truth. An opportunity soon arises for Tinkle to be rid of Kilmore. The young doctor spots May going onto the roof of the nurse's home and believes she is going to commit suicide after her encounter with Tinkle, unaware she intends to sunbathe. In trying to rescue her, Kilmore creates an unfortunate scene that leaves him subject to claims of sexual deviancy.




Summoned to a hearing with the hospital governor, Kilmore attempts to reveal the truth, but Tinkle and Matron deny the accusation, revealing that May has since been made to leave. Nurse Clarke knows what really happened on the roof. With his reputation in ruins, Kilmore decides to resign, prompting Clarke to tell the male patients what she knows. Roper, disgusted with what was done to Kilmore, arranges for the whole ward to seek revenge on Tinkle and Matron, with Biddle asking Mavis for the help of the women patients. Conducting a nocturnal mutiny, the patients swiftly subdue Sister Hoggett, preventing her from alerting the orderlies. The group bring along Bigger who, after mishearing Tinkle's conversation with his assistant, believes he is dying. This has prompted him to marry Chloe. The gang capture Tinkle and Matron. While the women force a confession from Matron by making her endure a blanket bath, the men force Tinkle to confess after threatening him with an enema, after several other methods fail to work.




The next day, Dr Kilmore is appointed the new hospital registrar while Tinkle is reduced to a simple doctor. Mr Barron, now fully recovered and cured, leaves with his wife and their new baby. Meanwhile, Bigger prepares to leave the hospital with Chloe, but resents the bickering he must endure and the fact that he must give up his work as a faith healer. On the way out, Bigger deliberately falls on the steps and injures his back again. As he is being brought back inside the hospital, he breaks the fourth wall to inform the audience he hopes he will be staying for a long time.