When advertising exec Phil Winslow (Lee Pace) gets an offer to head the account for a California-based dog-food company he uproots his wife (($Judy Greer) three kids and their beloved Great Dane Marmaduke (voiced by Owen Wilson) from Kansas to the Sunshine State. Once there the big canine befriends a group of mutts at the local dog park but after a surfing competition brings Marmaduke celebrity he turns his back on his new pals. Eventually a disaster helps the oversized hound and Phil learn about the importance of family and friendship.