He was well known in the Netherlands for his live performances and appearances in Dutch popular media.
His prominent role in the cultural life of Rotterdam earned him the nickname "night mayor of Rotterdam.
He was a Dutch poet, spoken word poet and writer. His poems cover topics such as life in the city of Rotterdam, drug use, and jazz.
He collaborated with musicians and bands such as Herman Brood, Benjamin Herman and Bas van Lier to record and perform his poetry.
Deelder also wrote scripts for the comic book series Amber en Akka and Professor Hilarius, drawn by Rob Derks. He furthermore inspired a celebrity comic of his own, Juul Deeldert, drawn by Vick Debergh.