Pataki was born in Youngstown, Ohio. His father was Hungarian. He attended the University of Southern California with a double major in political science and drama. His career was launched at a summer stock festival in Edinburgh in 1966, with a review that read, "Michael Pataki went beyond the bounds of mere nationality in his tense and moving interpretation of Jerry in The Zoo Story". Pataki was so well loved that at a reception for the theatre group acclaimed English actor Laurence Harvey, whom Pataki had never met, said he was magnificent and gave him a kiss on the mouth.

Pataki has also had his fair share of B movie roles in titles such as The Last Porno Flick (1974), and Carnal Madness aka Delinquent Schoolgirls (1975) with George Buck Flower and Colleen Brennan, and others. In Dracula's Dog (1978), he played opposite Reggie Nalder and José Ferrer as a descendant of Dracula who is stalked by a vampiric Doberman Pinscher. His other horror titles included Grave of the Vampire (1972), The Baby (1973), Dead and Buried (1981) and Halloween 4: The Return of Michael Myers (1988). He also directed Richard Basehart in Mansion of the Doomed (1976).

Pataki's film credits included Airport '77 (1977), Spider-Man (1977), Love at First Bite (1979), The Onion Field (1979), Raise the Titanic (1980), Remo Williams: The Adventure Begins (1985), and many others. He also appeared in Rocky IV (1985), as Nicoli Koloff, the Sports administrator for the Soviet team.

Pataki directed the 1977 film version of Cinderella. He also co-produced the filming of the stage presentation of Pippin with David Sheehan, starring william Katt. Pataki was also an accomplished voice over Artist, playing the part of the Sewer King in an episode of Batman: The Animated Series. He was the voice of George Liquor for The Ren & Stimpy Show production house Spümcø until 1997. Pataki died from cancer on April 15, 2010 at the age of 72.