Short stories
Agatha Christie wrote many short stories featuring Hercule Poirot, some of which were first published individually in magazines and newspapers. In book form, however, every short story was published as part of a collection.
Short story collections

Poirot Investigates
1924 (UK)
1924 (UK)

Poirot Investigates
1925 (US)
1925 (US)

Murder in the Mews
1937 (UK)
1937 (UK)

The Labours of Hercules
1947 (US, UK)
1947 (US, UK)

Three Blind Mice and Other Stories
1950 (US)
1950 (US)

The Under Dog and Other Stories
1951 (US)
1951 (US)

The Adventure of the Christmas Pudding
1960 (UK)
1960 (UK)

Double Sin and Other Stories
1961 (US)
1961 (US)

Poirot's Early Cases
1974 (UK)
1974 (UK)