André Marx studied German, linguistics and arts at the University of Osnabrück from 1994 to 1996. He then concentrated entirely on writing books.

Marx is a fan of the original U.S. stories of The Three Investigators and as such wrote his first The Three Investigators book, The sunken ship, in 1995 in his free time. Two years later, his first book, The Three Investigators – Poltergeist.