Soon after their wedding, John and Jenny Grogan escape the winters and relocate to a cottage in southern Florida. Jenny is the succesful and not for John .When John senses Jenny is contemplating motherhood, his friend and co-worker Sebastian Tunney suggests the couple adopt a dog to see if they're ready to raise a family.Editor Arnie Klein offers John to write a column for living. Without any clues, John realizes the misadventures of Marley might be the perfect topic for his first piece. Arnie agrees, and John settles into his new position.Marley continues to wreak havoc on the household, providing John with a wealth of material for his column, which becomes a hit with readers and helps increase the newspaper's circulation.When Jenny having born 3 child, She starts growing impatience with Marley and John, who asks Sebastian to care for the dog when Jenny insists they give him away. She quickly comes to realize he has become an indispensable part of the family and agrees he can stay. John celebrates his 40th birthday. Life is idyllic until the aging Marley begins to show signs of slowing down. When it becomes clear surgery will not help his debilitating condition, the dog is euthanised and buried.