During the Assault on the castle in the game's Prologue, a dead body can be found near the large iron gates to the castle. The body is wearing a white, hooded cloak tied with red and brown garments and it appears that the cause of death was falling from a great height into a cart of hay. Geralt comments upon finding the corpse: "Hmm... Guess they'll never learn.", and then receives one point in the Assassination Attribute. This is a reference to the first Assassin's Creed game and its protagonist, Altaïr.

In Russia, the game's publisher released a Witcher nude calendar to help promote the game. The calendar featured Ukrainian model Klodi Monsoon as the character Triss Merigold from the game.

Near the beginning of chapter 2 on the Iorveth path, after Spoiler:Saskia gets poisoned, Phillipa will say that she will need one of the 20 rings of power to cleanse the poison. Iorveth then remarks "One to bring them all and in the darkness bind them", and soon after Geraldt will also remark "and then I'll have to run barefooted to the top of a volcano." Which is a reference to the Lord of the Rings series.

During the American President Barack Obama's tour of Europe in 2008, Polish Prime Minister Donald Tusk gave him several gifts in celebration of his visit to Poland, one of which was a copy of The Witcher 2: Assassins of Kings collector's edition.