Fürmann was born in Berlin-Kreuzberg. By the age of 15 he had lost both his parents. At 17, he had a serious accident while train surfing, and had to spend six weeks in the hospital as a result. Fürmann left school after his Mittlere Reife and after that worked as a waiter and a bouncer. In 1991 he went to New York City and studied acting at the Lee Strasberg Theatre Institute.