He published his first works at the age of fourteen, and published his debut poetry volume Na Złotym Polu [On the Golden Field] in 1912. After graduating from secondary school, he studied Polish philology from 1916 to 198 at the University of Warsaw. He was the co-editor of the periodical Pro Arte et Studio and its continuation Pro Arte; he published numerous poems and reviews there, and also collaborated with Sowizdrzał (1917-1919). He co-created the literary-artistic cabaret Pikador (1918) and was one of the founders and creators of the poetic group Skamander – he gave the introduction to its first performance (6th December 1919); the name of the group was his idea as well. Between 1920 and 1923, he published poetry, literary and journalistic articles and reviews in Skamander magazine.
In 1921 he attempted suicide and was rescued and treated in numerous hospitals and sanatoriums. He published in Kurier Poranny (1922, 1927-1928), Pani magazine (1923-1926), Wiadomości Literackie (1924) and Głos Prawdy (1926-1929). Between 1926 and 1929, he was the editor of the satirical magazine Cyrulik Warszawski, and in 1929 he was the secretary of the editorial office of Pamiętnik Warszawski, published by Wacław Berent. He was a member of the board of the Trade Union of Polish Writers and the general secretary of the PEN Club. He received the Polish Society of Book Publishers' Award (1925) and the Złoty Wawrzyn PAL award (1935).
Between the years 1930 and 1939, he lived in Paris, where he was the cultural attaché of the Polish embassy. After the defeat of France, he went through Spain and Portugal to Brazil to move to the United States in 1941 and live in New York. From 1941 to 1947, together with Kazimierz Wierzyński and Józef Wittlin, he edited Tygodniowy Serwis Literacki Koło Pisarzy z Polski, Tygodniowy Przegląd Literacki Koło Pisarzy z Polski and after 1943, Tygodnik Polski as well. He was the co-founder of the Polish Scientific Institute, where he gave lectures and cooperated on films. He was a regular collaborator of Wiadomości Polskie Polityczne i Literackie published in London. In 1952, he received an award from the Association of Polish Writers in Foreign Countries. He died by suicide.
From 1917 through 1920 Lechoń wrote rhyming political satire – in works collected in the book Rzeczpospolita Babińska: Śpiewy Historyczne [The Babińska Republic: Historical Songs], he mocked the political spheres of the puppet ‘Kingdom of Poland’ created by the Germans in 1917, as well as the later relations in free Poland. These works were very popular at the time, but as they were strongly linked to the current political reality, they quickly lost their readability.