Zamachowski graduated the actor's faculty in "PWSFTViT" in Łódź. He began his acting career in 1981 and in 1989 had a co-starring role in Part Ten (Thou Shalt Not Covet Thy Neighbor's Goods) of director Krzysztof Kieślowski's film series, The Decalogue. Four years later, Kieślowski cast him as the lead character, "Karol Karol", in Three Colors: White, the second of his acclaimed Three Colors trilogy. Between 1985 and 1997 he performed at The Studio Theater, and since 1997 he is an actor of the National Theater in Warsaw.