Almost every cast member knew who A was except Lucy Hale. They were afraid she would tell someone else because she's not good at keeping secrets.
The doors you see in Aria's bedroom leads to Spencer's bedroom on set.
The view of the whole town is used in Pretty Little Liars, Witches of East End, The Carrie Diaries, Gilmore Girls, Bitten, Hart of Dixie, The Vampire Diaries, Riverdale, Wednesday, and Ghost Whisperer.
Lucy Hale (Aria) auditioned for the role of Hanna, which eventually went to Ashley Benson.
The theme song for the show, 'Secret' by The Pierces, was suggested by Ashley Benson.