Per Sanderhage started his comic career working as an editorial assistant for the publishin house Interpresse in the early seventies. Since 1980, he has worked as an editor, translator, writer and artist for the Copenhagen Press Agency. He has made the daily comic strip of 'Petzi' ('Rasmus Klump'), created by Carla and Vilhelm Hansen. He collaborated on the historical comic series 'The Scyldings' ('Skjoldungerne') with Henning Kure and Orla Klausen. In 1983, he made one episode of the daily newspaper strip 'Felix', created by Jan Lööf.
In 1987, he created the charming, humorous and clever mouse story 'Little Town of Kopenhagen' ('Kjøwenhavnstrup') for the newspaper B.T., as well as the detective 'Colt', together with Peter G. Heydenreich. Sanderhage has worked with Eduardo and Vicente Vaño on the action comic 'Bravo Tango', as well as the LEGO advertising comic 'Sjørøverne og gullmedaljongen'. Besides his activities as a comic artist and writer, Per Sanderhage has written short stories and several novels. In 1982, he was awarded the Science Fiction Circle's Illustrator Prize.