As a young man he worked in his spare time for the literary agency of his uncle,[1] Laurence D'Orsay (in fact his first cousin by marriage), in Los Angeles before selling his first story, "The Graveyard Rats", to Weird Tales in early 1936.

Among Kuttner's most popular work were the Gallegher stories, published under the Padgett name, about a man who invented high-tech solutions to client problems (assisted by his insufferably egomaniacal robot) when he was drunk, only to be completely unable to remember exactly what he had built or why after sobering up.

[5] William S. Burroughs's novel The Ticket That Exploded contains direct quotes from Kuttner regarding the "Happy Cloak" parasitic pleasure monster from the Venusian seas.

Mary Elizabeth Counselman believed that Kuttner's habit of writing under widely varied pseudonyms deprived him of the fame that should have been his.

"[6] According to J. Vernon Shea, August Derleth "kept promising to publish Hank's and Catherine's books under the Arkham House imprint, but kept postponing them.

"[7] A friend of Lovecraft's as well as of Clark Ashton Smith, Kuttner contributed several stories to the Cthulhu Mythos genre, based on the writing of the former and added to, among other authors, by the latter.

[8][9] Kuttner added a few lesser-known deities to the Mythos, including Iod ("The Secret of Kralitz"), Vorvadoss ("The Eater of Souls"), the Hydra and Nyogtha ("The Salem Horror").

The Kuttner stories included are: "The Secret of Kralitz", "The Eater of Souls", "The Salem Horror", "The Jest of Droom-Avesta", "Spawn of Dagon", "The Invaders", "The Frog", "Hydra", "Bells of Horror" and "The Hunt" - thus, all the Mythos stories which had appeared in the special Kuttner issue of Crypt of Cthulhu, plus "Spawn of Dagon" and "The Invaders".

Price points out in his introduction to the volume that "Henry Kuttner's own private corner of the Cthulhu Mythos was, then, apparently derived in about equal measure from Lovecraft, Bloch, Zoroastrianism, and Theosophy.