"Doctor in Distress" is the fifth of the seven films in the "Doctor" series, and focuses on Sir Lancelot Spratt, Simon Sparrow's old teacher and sometimes nemesis. When the eternal bachelor Sir Lancelot injures his back and falls in love with his physiotherapist Iris Marchant, he becomes very distressed and turns to Simon for help. Simon, who now is a senior doctor at fictional Hampden Cross Hospital and hopelessly in love with aspiring actress Delia, sends him to a nature cure clinic in a vain attempt to help him lose weight, but Sir Lancelot can't get Iris off his mind and has her followed, first by a private investigator and eventually by himself. When he finally proposes, she rejects him and marries an old army major, which distresses Sir Lancelot even more.

Dirk Bogarde
as Dr. Simon Sparrow

Samantha Eggar
as Delia Mallory

James Robertson Justice
as Sir Lancelot Spratt

Donald Houston
as Major Tommy Ffrench

Barbara Murray
as Iris Merchant

Dennis Price
as Dr. Blacker

Mylène Demongeot
as Sonja Stromberg / Helga Stromberg

Jill Adams
as Genevieve Milton

Timothy Bateson
as Mr. Holly

Jessie Evans
as Mrs. Parry