Jay: He is fifteen "and a half" years old. He insists on the "and a half". The death of his mother forces him to be more mature than he is ready to be when his father leaves him and his younger brother with his family so he can sell scrap iron during World War Two. The play tells his coming-of-age story. Originally played on Broadway by Jamie Marsh.
Arty: Jay's younger brother, he is 13 "and a half" years old. More of an observer than the rest of his family, he often goes with the flow of things, but also can be a little childish. Originally played on Broadway by Danny Gerard.
Bella: Jay's thirty-five-year-old aunt. She is sometimes a bit off-center and is mentally challenged, but despite this she is also loving and protective of her nephews. Much of the second half of the play focuses on her attempts at independence from her stern mother. Originally played on Broadway by Mercedes Ruehl.
Louie: Jay's flamboyant, jovial uncle, in his late 30s, who comes to live with the family when he is hiding from the local mob. He is considered by Grandma Kurnitz to be the "survivor" of the family. He has a strong, mercurial nature, and a certain underlying dark side, which the kids uncover in the second act of the play. He works as a "bag-man" for the mob. Originally played on Broadway by Kevin Spacey.
Grandma Kurnitz: Jay's grandmother. A very old and stern woman, an immigrant from Germany. Owing to her harsh childhood, she has always been very intolerant of what in others she calls "weaknesses". She is blunt, sometimes even in a funny way, and always knows what is going on with the people around her. Originally played on Broadway by Irene Worth.
Eddie: Jay's middle-aged father. After the death of his wife, he is forced to send his two sons to live with their grandmother, while he repays his large financial debts. He is shown to be, much like his sisters, a nervous wreck around Grandma. Originally played on Broadway by Mark Blum.
Gert: Jay's aunt, and Grandma's daughter. She is a very interesting addition to the family. Her most noticeable issue is that when she breathes she has a tendency to suck in while still speaking, as a result of trauma instilled in her by Grandma from a young age. Originally played on Broadway by Lauren Klein.