Multi-millionaire Phillip Drummond, who has agreed to the death-bed wish of his housekeeper to raise her two small sons as his own, welcomes 8-year-old Arnold and 12-year-old Willis into his lavish penthouse.

Arnold's eavesdropping leads to trouble when a misunderstanding causes Willis and him to think that Mr. Drummond no longer wants them around. He has heard Drummond tell a social worker that "black children belong with black families".

Mr. Drummond's socialite and rather snobbish mother arrives and finds there's a lot she doesn't like about her son's new sons, but she soon learns a valuable lesson about what's really important in a person.

When Mr. Drummond tries to get Arnold and Willis into an exclusive prep school, it turns out to be just a little too exclusive for everyone's tastes.

Mr. Drummond's decision to punish Arnold for a prank with a spanking becomes a learning experience for Willis too, when he insists that he be the one to spank Arnold.

When Arnold loses his favorite doll, he makes sure that his misery is shared equally by the various members of his household, who soon try everything to get it back.