Jørgen Mogensen started making comics after meeting the cartoonist Cosper in 1944. It was in Cosper's magazine 'Hudibras' where his first work was published. After working for some other magazines, he started his successful series 'Poeten og Lillemor' ('The Poet and the Little Woman'). This daily comic about a typical Danish family has been published in several Copenhagen newspapers, and later on, it appeared as a weekly comic in Hjemmet.
At the same time, Mogensen started several other series. He made comics about office girls, such as 'Roselil og hendes mor' ('Roselil and her mother') 'Lullubelle' and the social satire 'Esmeralda'.
In 1985, Jørgen started making comics based on folktales, as in 'Elvis Mælketand'. When Rune Kidde lost his eye-sight in 1990, Jørgen Mogensen assisted him as an artist on several series.