Except for season 1, the theme song has been modified for a specific holiday on the 13th episode of each season. For example, season 2, 3 and 4 had a Halloween theme while season 5 had a Christmas theme.
Vanessa Ray and Troian Bellisario share several scenes. They have appeared in Suits too but never together. Ironically, both women played Patrick J. Adam's love interest who is Troian's real life husband. Patrick has appeared in a bit role in Pretty Little Liars as Ezra's friend, but not shared scenes with either Troian or Vanessa.
Shay Mitchell, who plays Emily Fields almost got the part of Spencer (played by Troian Bellisario) instead, and Brant Daugherty, who plays Noel Kahn originally auditioned for Ezra, but though he is actually 13 months older than Ian Harding (who landed the role), they didn't think he looked old enough. They called him back to re audition for Noel.
Ashley Benson (Hanna) and Shay Mitchel (Emily) are best friends since the show aired in 2010,so much so that they are popularly known as "ButtahBenzo".ButtahBenzo is part Shay (Buttah) and Ashley Benson (Benzo).
Both Claire Holt (Samara) and Bianca Lawson (Maya) played love interests of Shay Mitchell's character, Emily. Nathaniel Buzolic played Dean, the subtance abuse counselor who helped Spencer. They all had roles as supernatural characters on The CW's "The Vampire Diaries" (2009).
Apart from the many references to literature in the show, several of the characters share names with famous writers. Ezra Fitz shares his name with both Ezra Pound (an American poet) and F. Scott Fitzgerald (an American novelist). Spencer Hastings shares her name with the early modern English poet Edmund Spenser, while Byron Montgomery shares his name with the English Romanticist poet Lord Byron and Canadian author Lucy Maud Montgomery.
In season 2 episode 12, right after Dr. Sullivan leaves A behind at the diner, a waitress refers to A as "pretty eyes". This waitress' name tag, for a moment, shows the name "Marlene" - a reference the show's creator, I. Marlene King.
There was a Turkish remake of Pretty Little Liars (2010) named "Tatli Kucuk Yalancilar". The show started on July 6, 2015 and ended on October 3, 2015 on Star TV after season 1, which consisted of 13 episodes.
Both Troian Bellisario and Ian Harding have guest starred in the NCIS series. Troian guest starred in 2 episodes of the original and Ian guest starred once in the first season of the spin-off 'NCIS : Los Angeles'. Troians stepbrother is the main character in NCIS.
The top view of the whole town is used in Pretty Little Liars, Witches of East End, The Carrie Diaries, Gilmore Girls, Bitten and Hart of Dixie. The set itself is used on Pretty Little Liars, Gilmore Girls, and Hart of Dixie.
When Toby starts living in the apartment above the 'Brew' Spencer goes there to prepare a surprise dinner for their first anniversary there is a framed picture on the wall of 'Luna Park'. Luna Park Sydney is an amusement park located in Sydney, New South Wales, Australia. Luna Park is located at Milsons Point, on the northern shore of Sydney Harbour. Reference Wikipedia Opened: October 4, 1935
In the books Spencer is related to Alison (and Courtney). But because Peter Hastings and Jessica Dilaurentis were having an affair, in the tv-show it's Alison's older brother who is Spencer's half sibling
The series doesn't follow the books; characters who were killed on the show, e.g. Maya, weren't killed off in the books. For Toby, however, it's vice versa; as he was killed in the books, but not on the show. The creators originally planned to kill Toby, but due to his character's popularity, they decided not.
There is a special episode called " A Liars Guide to Rosewood" which Mona narrates how she planned the whole thing from the beginning. This episode shows bits and pieces of Season 1,2& 3. It featured before Season 4 started.
Hannah was the first person to think Ali was still alive in season 1. Everyone thought she was crazy. She was also the first to think Elliot was still alive in season 7 and everyone thought she was crazy then too.
A was suppose to be revealed on the season finale of season five as promised by show creators. A was not actually revealed. This was later cleared up by Marlene King, who specified that ABC Family make the promo trailers which teased the "Big A Reveal" and it was out of their control.
On Tuesday, August 11, 2015, in the season 6 mid-season summer finale "A" was finally revealed, along with "Red-Coat" and "The Black Widow" "A" is CeCe (or Charles/Charlotte) and "Red-Coat" and "Black Widow" are both Sarah Harvey.
Julian Morris, who plays Wren Kingston, starred in the 2009 film Sorority Row, which has a similar plot to the show, only the sisters are killed. Wren has been one of the biggest suspects in PLL, and was previously accused of being A. He was revealed as the killer in the film.