Frentzen began karting at the age of twelve, after his father brought him his first kart, and made an extraordinarily successful start. In 1981, aged fourteen, Frentzen won the German Junior Kart Championship. Two years later, Frentzen entered the CIK Asia Pacific Championships in Australia driving a Dino although he did not finish. In 1984, he finished runner-up in the 100cc class. He was funded and supported by his father—a funeral director—who also acted as both team boss and head mechanic.