Dr. Leonard Green is the father of Rachel Green. He is an overbearing perfectionist who demands that anything his children do reap instant, flawless results. He and his wife divorced shortly after Rachel left her fiance Barry at the altar; her mum told Rachel, "you didn't marry your Barry, honey, but I married mine." While he and Rachel have a fairly fractious relationship, he has said to his friends and youngest daughter Jill (but not to her) that she is the only one of his children he is proud of. He hates Ross and is highly critical of him, especially after he finds out Ross made Rachel pregnant and at the same time would not marry her. Like many of the characters on the show, including his wife and daughter, Dr. Green is a traditional Jewish stereotype: the overbearing, oft-critical doctor. Ron Leibman once said of his character: "I may have won a Tony... but everyone asks, 'Aren't you Rachel's Dad?'"
Dr. Green is also a hypocrite - a smoking cardiologist, he scared a young Rachel with smoker's lungs yet kept puffing away, perhaps leading to his heart attack. Dr. Green was first mentioned in the 23rd episode, "The One with the Birth." Chandler said to Rachel, "What is it with you and doctors? Is your dad, like, a doctor?" Rachel replied, "Yeah. Why?" This was not the first episode to mention Dr. Green, but it was the first mention that he was a doctor. He was shown in the episode "The One with the Two Parties", where he drops by to wish his daughter a happy birthday. However, this kind gesture is ruined when he seizes the party as an opportunity to explain his reasons for the divorce to Rachel. In "The One with the Stripper," Dr. Green learns that Rachel is pregnant. The last scene featuring Dr. Green was in "The One Where Joey Speaks French," in which he has a heart attack. Played by Ron Leibman