He made his debut with the collection sent på jorden ("late on earth") in 1932, written during an extended stay in Paris in 1929–1930, which was too unconventional to become widely appreciated and described by its author as capturing a period of suicidal thoughts and apocalyptic moods.

Both the volumes are influenced by surrealism and show a violent, at times feverish torrent of images, deliberate breakdown of ordered syntax and traditional poetic language and a defiant spirit bordering on anarchism ("cut your belly cut your belly and don't think of any tomorrow" runs the black humorous refrain of a poem called "fanfare" in sent på jorden; a collection that eschews capital letters).

Though he came from an upper-class background, Ekelöf had never felt committed to it – his father had been mentally ill and when his mother remarried, Ekelöf strongly disapproved of his stepfather, and by extension of his mother; he had become a loner and a rebel by his teens and would never feel at ease with the mores of the established upper and middle classes or with their inhibitions and what he perceived as their hypocrisy and back-scratching.

[2] Swedish critic Anders Olsson described Ekelöf's turn to poetry as a choice of "the only utterance that doesn't expurge the contradictions and empty spaces of language and of the mind.

[4] This was followed by the acclaimed works,[5] the prose book Promenader (1941, "Walks"), the disillusioned[4] Non Serviam (1945) (its Latin title meaning "I will not serve") and Om hösten (1951, "In autumn").

[4] In April 1958, Ekelöf was elected a member of the Swedish Academy, succeeding author Bertil Malmberg on chair 18 in December the same year.

Ekelöf made some substantial re-edits of the text and sequence of poems in later collected editions and anthologies of his work, especially relating to his 1930s books.