Peter Madsen started his comics career at a very early age. In 1973, at a Comics Festival in Copenhagen, he attracted the attention of the editor of Interpresse, and his first comics were published in Seriemagasinet. In 1976, he worked together with Rune Kidde and others, on the fanzine Knulp. In 1977, Interpresse's album editor Henning Kure asked him to do the artwork on the humorous comic series 'Valhalla' (written by Hans Racke Madsen). After the second album appeared in 1982, Peter Madsen was involved with the production of the animated film of 'Valhalla', which was released in 1986. In 1992, the seventh album of the series was chosen as the best album of the year by the public at Comics Mekka in Ballerup.
More of Peter Madsen's artistic talents can be seen in the album 'Along the Road' ('Hen a Vejen') and his erotic work in 'Danish Delights' ('Danske Fristelser'). His experiences as a young medical student were collected in the album 'Greenland Diary' ('Grønlands Dagbok') in 1990. In 1995, 'The Son of Man' ('Menneskesønnen'), Peter Madsen's interpretation of the New Testament appeared, and it was chosen as the Best Color Comic of the Year and awarded the Christian Comics Prize in 1996. Besides his comics, Peter Madsen has illustrated children's books, including Henning Kure's 'Troll Story'. In 1999 another biblical retelling was published when Madsen interpreted The Book Of Job in the album 'Historien om Job'. The critically acclaimed 'Historien om en mor', an interpretation of the Hans Christian Andersen story 'The Story Of A Mother', was released in 2004.