1978 yilda sahnada chiqishni boshladi. Teatr karerasi davomida Ontario, Alberta va Britaniya Kolumbiyasi teatrlarida ishlagan. 70-yillarning oxirida kino debyuti bo'lib, "Disneyland" ("Dizneyland") va "The Beachcombers" teleseriallarida rol o'ynagan.
1980 yilda Chok Jon Gillerning "Mr. Patman" ("Mister Petmen") dramasida politsiyachi rolini ijro etgan. Ikki yildan keyin Filipp Borsosning "The Grey Fox" ("Sery lis") vesternida bir rolni o'ynagan. 80-yillarda Gari Chok "Danger Bay" ("Xavfli ko'rfaz"), "MacGyver" ("Secret agent Makgayver"), "Into Thin Air" ("Osmonda"), "Stingray" ("Stingrey"), "Spot Marks the X" ("It o'g'li"), "Airwolf" ("Havo qulog'i"), "Sworn to Silence" ("Sukut qasam"), "21 Jump Street" ("21 Jump-strit"), "Wiseguy" ("Aqlli yigit") va boshqa ko'plab televizion filmlar va seriallarda ishtirok etgan.
1983 yilda aktyor "The Legend of Hiawatha" animatsion filmida ovozli ishtirok etgan. Keyinchalik Gari Chok "Doragon boru: Shenron no densetsu" ("Drakon zambil: Qonli yo'qotish la'nati"), "Captain N: The Game Master" ("Kapitan N: O'yin ustasi"), "The New Adventures of He-Man" ("He-Manning yangi sarguzashtlari"), "Dragon Quest" ("Drakon izlanishi"), "Exosquad" ("Kosmik qutqoruvchilar leytenanti Marsh"), "Double Dragon" ("Ikki drakon"), "The Adventures of Sonic the Hedgehog" ("Sonic the Hedgehogning sarguzashtlari"), "Conan: The Adventurer" ("Konan: Sarguzasht izlovchi"), "ReBoot" ("Qayta yuklash"), "Leo the Lion: King of the Jungle" ("Arslon Leo, Jungle qiroli"), "Transformers: Cybertron" ("Transformers: Kiberton") va boshqa ko'plab animatsion filmlarda qahramonlarning ovozini bergan.
Gari Chokning eng mashhur to'liq metrajli filmlari: "Bang Bang You're Dead" ("Pif-paf, sen o'liksan"), "Watchmen" ("Qo'riqchilar"), "Fierce People" ("Shafqatsiz odamlar"), "It" ("Bu"), "Eight Below" ("Sakkizta pastda") va "Blonde and Blonder" ("Blondinka va blondinka").
