Trivia

Ricky Gervais and Katt Williams both did full motion and voice capture for their brief appearances in their own comedy skits at the Split Sides Comedy Club and on the in-game television.

With an estimated budget of $100 million (US), it held the record for the most expensive video game produced at the time of its release.

According to the LCPD online database, Little Jacob's full name is Jacob Hughes, Real Badman's given name is Teafore Maxwell-Davies, and Playboy X's given name is Trey Stewart. It also establishes Mrs. McReary's first name as Maureen.

The first of the series to feature sexual acts actually being performed by a prostitute on the protagonist. Other Grand Theft Auto games featured the player and the prostitute sitting in the front seats, motionless, as the player's vehicle rocked to and fro. Grand Theft Auto V (2013) took it a step forward by having the strippers being topless when giving lapdances to the three protagonists. The protagonists of Grand Theft Auto V can also take some of the strippers home for a booty call and the strippers number will end up being saved in the protagonist's phone.

One can access the LCPD online database by going to the LCPD website on the in-game internet, scrolling to the bottom of the page, and clicking on 'Database'. The database is accessible from the very beginning of the game.

If the player goes to a certain level of the Statue of Happiness, there will be a non-solid door with a plaque next to it reading "No Hidden Content this way". If the player goes through the door, there is a ladder leading up to a gigantic beating heart with chains attached to it. It can be shot and blood will shoot out of it although the player can eventually realize the heart is indestructible.

Information on the protagonists of the following three Grand Theft Auto games can be found in the LCPD online database: Johnny Klebitz, of Grand Theft Auto IV: The Lost and Damned (2009); Huang Lee, of the Nintendo DS game Grand Theft Auto: Chinatown Wars (2009); and Luis Fernando Lopez, of Grand Theft Auto IV: The Ballad of Gay Tony (2009). Both Klebitz and Lopez make cameo appearances in Grand Theft Auto IV (2008).

In some of the trailers and official artwork, Niko can be seen wearing gloves, they aren't accessible in the game without mods.

The storyline intersects with the events of both Grand Theft Auto IV: The Lost and Damned (2009) & Grand Theft Auto IV: The Ballad of Gay Tony (2009).

Chinese signboards are seen throughout the islands. Many of them are Homophones associated with slangs and dirty jokes in Hong Kong culture. For examples, "Bill Sze Accounting" can be read as "Poop-your-pants Accounting" in Cantonese. While "167" in Cantonese is known as "A piece of dick," a dirty way to say "dumb." "Mr. Mo Driving" can be translated ironically as "Manless-driving" or "Autopilot." There are also sarcastic jokes about the names, such as "Loan-shark-king Financial Loans," "Alopecia Hair Salon" and "Super Real Jewewllery," et cetera.

The boat that Niko Bellic arrives on is named 'The Platypus'. The platypus is an animal that is native to Australia. Numerous references have been made about Australia in previous Grand Theft Auto games including references to the fictional Australian-American war.

A teaser site for WKTT, one of the in-game radio stations, invited people to call a telephone number to talk about how they felt about the state of America in the style of a talk radio phone-in. The best rants were included in the final version of the game.

At the beginning cutscene of the game, there is a poster of Grand Theft Auto: Vice City (2002)

Wu "Kenny" Lee can also be found in the LCPD online database even though he was not introduced until Grand Theft Auto: Chinatown Wars (2009) for the Nintendo DS.

The stand up Katt Williams does at the split sides comedy club is from his stand up movie Katt Williams: American Hustle (2007).

The Perestroika cabaret club in Broker is owned by Russian mafia member Mikhail Faustin. Perestroika was a name given to the political and economic reforms of the Soviet Union by then-General Secretary Mikhail Gorbachev. Not only is it strange that they both share the same name, it should also be noted that the literal meaning of Perestroika is "restructuring", possibly referring to either the rebuilding of the old ways in the USSR in Hove Beach, or referring to the restructuring of one's life in America. Also, there is a restaurant in Broker called "Little Gorbachef's", an aobvious reference to Mikhail Gorbachev.

The character of Brian Meech, one of the random characters that Niko can meet on the street, tells Niko on their third meeting that he resorted to performing oral sex on people to support his heroin habit. This is close to the same story as Rick Shapiro, who features on the PLR radio station within the game.

When shooting civilians/enemies/police, often times they will be incapacitated rather than outright killed (unless shot in the head or harmed further). They may writhe on the ground, call out to the protagonist character (usually pleading for their life), and even attempt to stand up only to limp away wounded. Enemies marked with a mission objective marker (whom the player must eliminate) are no longer considered a threat when in this incapacitated state, most likely because they always drop their weapon.

The darkest entry in the Grand Theft Auto series, and the first installment to have a close relative or person of the protagonist sacrificed. This trend went on to Grand Theft Auto V (2013) as well, but there the players have the choice to avoid a sacrifice, where in Grand Theft Auto IV it is programmed and is out of control of the players.

There are online rumors that claim that an extra mission would be found after the last mission of the game. According to the rumors, if the players chose to spare Darko Brevic in the mission "That Special Someone", he would later reappear in the game and send emails to Niko, asking where Ray Bulgarin's diamonds are (as also explained in the game's DLC expansion, The Ballad of Gay Tony). If Niko would reply negatively, a threat would be sent to Darko, and in return he would threaten Niko back, saying that his cousin Roman would be kidnapped. If the player chooses and finishes the mission "If the Price is Right", Roman gets killed in "Mr. and Mrs. Bellic", and Brevic would instead kidnap Niko's girlfriend Katie. This mission would only trigger after the last story mission "A Revenger's Tragedy". An enraged Niko would carry out a rescue operation on board the Platypus ship with Packie and Little Jacob. After finally finding Darko, he would reveal that he had killed Katie. Niko would then brutally execute Darko. If the player chose and finished the mission "A Dish Served Cold", Katie would die instead of Roman in "Mr. and Mrs. Bellic", and Darko would kidnap him as promised. Niko would team up with Packie, Little Jacob and Dwayne Forge (if he was spared in "...The Holland Play") and rescue an injured Roman. Niko would then fatally injure Darko, but would leave him to die instead of killing him instantly.

The main characters in the series will meet each other at least once.