Pierson passed away of natural causes at Cedars-Sinai Medical Center in Los Angeles, said the Writers Guild of America, West, a group for which Pierson once served as president.

Pierson most recently co-wrote an episode of the critically acclaimed television show "Mad Men" that aired earlier this year, and he had roughly 20 writing credits in television and film.

But he is best known for "Dog Day Afternoon," which starred Al Pacino as a man who tries to rob a bank to pay for his male lover's sex change operation and becomes a hero to a crowd of bystanders during a standoff with police.

Pierson also directed the 1976 Barbra Streisand film "A Star Is Born" and several made-for-television movies. Aside from his Oscar win for "Dog Day Afternoon," Pierson also was nominated for Oscars for his writing on the 1965 Western "Cat Ballou" and 1967 prison drama "Cool Hand Luke."

"From great, great movies like 'Cat Ballou' 'Cool Hand Luke' and 'Dog Day Afternoon' to his joining the writing staffs of 'The Good Wife' and 'Mad Men' well past his 80th birthday, he's always shown us ... how to do it with class, grace, humor, strength, brilliance, generosity and joyful tenacity," said Phil Robinson, a member of the board of the Academy of Motion Picture Arts and Sciences.

Pierson, who was born in Chappaqua, New York, worked in advertising before he sold a story and changed careers to become a screenwriter.

He is survived by his wife, Helene, children Michael and Eve, and five grandchildren.

(Reporting By Alex Dobuzinskis; Editing by Eric Beech)

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