Villechaize suffered from dwarfism due to a thyroid dysfunction throughout his life despite his sergeant father's attempts to cure the disease in several institutions. After having his initial art training in France, he left for the USA, where he continued his career as an artist and photographer.
His first movie appearance was in Chappaqua in 1966, which was followed by several films including The Man with the Golden Gun, Crazy Joe, Seizure, and The Forbidden Zone.
Influenced by his health problems and troubles in his professional career, Villechaize became alcoholic and depressive in the last few years of his life. In 1993, he shot himself at his home, was found by his wife Kathy Self, and died in hospital in North Hollywood, California of his injuries.