Sara Shepard, the author of the Pretty Little Liars books, envisioned Rosewood residents to look and act differently from what they do in ABC's adaptation of the story. Aria, Spencer, Hanna, and Emily look nothing like their book counterparts. The casting took huge liberties when it came to secondary characters too, often dramatically changing their storylines or adding characters that don't exist in the books, for example, Caleb.
Even though many of the characters didn't look right in the show, it didn't affect the over-all experience. If anything, the show introduced more diversity than the books, which is always a good thing.
Mike Montgomery
It's hard to cast actors who look like two peas in a pod. The show's Mike and Aria could as siblings in real life, but in the books, they were supposed to be incredibly similar. Just like Aria, Mike should have pale blue eyes and dark hair.
Aria Montgomery
Lucy Hale's Aria Montgomery stayed the truest to her book version of all the main characters. The only difference is that she was supposed to be way taller. The show managed to capture her aesthetic quite well: she was an artsy type who radiated "I'm not like the other girls" energy.
She's a unique spirit, which is also reflected in Aria changed a lot of hairstyles in the series.
Lucas Gottesman
Lucas from the TV show was an overlooked shy boy with a crush on Hanna. He wasn't popular at all, but he was incredibly smart and good with computers.
If he was to look the way he should have, he'd be one of the most handsome guys. The book version of Lucas is athletic, tall, blonde, and blue-eyed. He even got to date his dream girl and it was he who ultimately broke it off.
Jenna Marshall
We are definitely not saying that Tammin Sursok, who plays Jenna Marshall, is not a stunning woman, but it's safe to say that the show downplayed her beauty considerably.
This character was supposed to be as beautiful as Snow White: dark hair, red lips, and pale skin. Jenna was supposed to be so beautiful that the rest of the girls' beauty faded in comparison, fueling them with jealousy.
Mona Vanderwaal
If Mona Vanderwaal's appearance stayed true to the books, she'd be a pale girl with blue eyes, freckles, and ashy blonde hair. As we all know, the TV show version of Mona has black hair and hazel eyes.
Mona was bullied by Alison in both versions of the story, and she went from being an unpopular nerdy girl to a powerhouse who rocks designer bags and high heels. She's done some pretty horrible things as well.
Toby Cavanaugh
The way Toby was at first introduced in the series is kind of what he is like in the books: a creepy ab who spies on girls while they get changed. In the show, it turned out that this was just mean gossip and that Toby is actually a decent guy with both some good and bad personality traits.
They are both pale and have dark brown hair, but the book version is said to be lanky, which is something we can't say for Toby from the show. The book version of Toby met a tragic end pretty soon: he overdosed and died.
Spencer Hastings
Troian Bellisario captured the essence of the group's brainiac perfectly, but the book version of Spencer actually has really long light brown hair and emerald green eyes.
While Melissa and Spencer aren't really on great on the show, they don't get along at all in the books. Spencer is very jealous of her sister, which is something that isn't as prominent on the screen.
Hanna Marin
Hanna Marin Rivers from the books is described as clearly the most gorgeous one. Since the entire cast of the show is drop-dead gorgeous, it's safe to say that her beauty is not something that defines Hanna as much in the show. She has dark eyes, dark hair, and she's super skinny in the books. Meanwhile, Hanna as we know her is blonde and has a really warm personality.
While Hanna from the TV show is one of the most likable Pretty Little Liars characters, the book version of Hanna is much less likable and very obsessed with the notion of being the most popular.
Emily Fields
Shay Mitchell is a dark-haired beauty, but she looks nothing like Emily from the books. When it comes to her appearance, book Emily is described as having strawberry blonde hair, green eyes, a light complexion, and a very muscular body, namely wider shoulders and stronger legs as all swimmers do. Her family is Irish Catholic and she has two sisters.
Emily's personality is also a little bit different: she comes across as much more insecure and weak than Shay's Emily does. To be fair, Emily started out as a pretty shy character, but she changed throughout the series into someone way more confident.
Wren Kingston
Wren Kingston, played by Julian Morris, was Melissa's handsome fiancé, and the fact that he kissed Spencer is one of those things that didn't age well at all from season 1. The show omitted an important fact about Wren: his name is actually Wren Kim and he is of British and Korean descent.
Therefore, he looks quite a bit different in the books: he has almond-shaped eyes and his hair is darker and longer. While Wren from the series has a pretty pale complexion, Wren Kim has warm-tanned skin.