Diff'rent Strokes took place in New York and centered around the happenings in the Drummond household. Philip Drummond was a widower and had a daughter, Kimberly. He was also quite wealthy and lived in the penthouse of a luxurious apartment building. His wealth was due to the fact that he was the president of Trans Allied, Inc.

However, the household was shaken up when Drummond's black housekeeper died and her deathbed wish was that he would take care of her two sons, Arnold and Willis Jackson. So, Drummond took both of them in and they became the sons Drummond never had.

Others in the cast included Mrs. Garrett the new housekeeper who later left for her own series, The Facts of Life. She was replaced by Adelaide, who was seen occasionally and she was later replaced by Pearl. In the seventh season, Drummond wed an aerobics instructor, Maggie McKinney and she moved in with her son, Sam, from a previous marriage.