This is the first time we see the opposite wall of the Ricardos' apartment.
KT Stevens, who played Mrs. O'Brien in this episode, was one of Vivian Vance's closest friends.
The phone operator that gives out the O'Briens' number is voiced by Lucy. It's her trademark nasal phone voice that she uses several times throughout the series when she wants to disguise her voice.
Hayden Rorke's television debut.
We learn that Lucy's middle name is Esmeralda.