The Hendersons are a happy family. Dad George (John Lithgow) and mom Nancy (Melinda Dillon) are returning home from a camping trip with their kids Sarah and Ernie when they run in to the strangest thing. From out of nowhere a strange creature runs in front of their car and they run it over, since they don't know what to do with it they strap it to their car and take it home with them. At home they give their new friend Bigfoot a nickname, they call him Harry and he turns out to be gentle and lovable. Unfortunately it isn't long before some sightings of him by people in the city create a frenzy and the family must decide whether or not they want Harry to stay with them, or whether they must let him return home to the wild where he belongs.