"Kaleidoscope in "K"" is a novella by author A. J. Cronin, initially published in 1933 in Cosmopolitan magazine.

[1][2] All of the action unfolds within twelve hours in a London hospital, and the story centres around the conflict between a young surgeon, Dr. Barclay, and the hospital chief, Dr. Selby.

A subplot is the rivalry between Barclay and a playboy physician, Dr. Preston, as they vie for the attentions of Miss Fanshawe, an attractive nurse.

The story comes to a tense climax as Barclay prepares for a delicate brain operation, a revolutionary procedure to which Selby is opposed.

The story was also printed in book form by various publishers, and it was also adapted into a 1934 film, Once to Every Woman.