Naughty Dog had to specifically request female focus testers for the game because they refused to let the game to be tested only on males.

There was an alternate ending that was cut from the game, but developers showed it at PAX Prime 2013. During filming of the scene, an impromptu song was made to fit the scene, which was played out in full by the actors.

An enemy which had been scrapped from the final game was an infected elephant which had tendrils of fungus extending from its legs and blooming mushrooms on its head. An encounter with the creature would have Joel, the game's protagonist, scrambling away from it.

Before deciding on the fungal infected enemies, early designs of the zombie-like creatures looked like bald, fanged beasts with stringy fungus growing off their back.

The cause of the zombie apocalypse is actually based on real life organisms. There is a parasitic fungus called Ophiocordyceps unilateralis, which is known for taking over an ant's mind and controlling its motor skills, basically making it a zombie. In The Last of Us, a fungus takes over most of humanity's minds, and turns them into zombies.

The game contains a number on a "Pest Control" poster that is actually a real life sex hotline.

In the chapter titled "Pittsburg", after you meet two new characters, if you check one of the rooms to the right there will be a Jak and Daxter doll sitting on the dresser, along with a Nathan Drake doll from the Uncharted series on the bed. Also, in the toy store there is a Jak and Daxter and an Uncharted board game sitting on the shelves on the walls oposite to were you entered. Finally, there are four unlockable Jak and Daxter items for Ellie to wear. A T-shirt, hoodie, backpack, and googles. All of these were previous titles made by Naughty Dog.