The Odd Couple had many real-life relatives of cast members appear on-screen (occasionally) as the characters' relatives. For instance, Oscar and ex-wife, Blanche, were real life husband/wife (separated but never divorced), Jack Klugman and Brett Somers, respectively. This episode is noted for featuring the Marshall siblings (as Myrna's brother and sister), as well as Penny Marshall's (then) real-life husband, Rob Reiner. Also Jack Klugman's son - Adam Klugman played the part of a young Oscar in an episode.
Garo Yepremian was the Miami Dolphins' placekicker from 1970-1978, a two time Super Bowl champion (VII/VIII), a First-Team All-Pro (1971/1973) and selected twice to the Pro Bowl (1973/1978).
The final episode filmed with actress Penny Marshall as Myrna, who gets married and quits her job as Oscar's secretary. However, a show's episodes are often aired out of sequence, and Myrna shows up once again as Oscar's secretary three months later in episode 14, "Two on the Aisle."