A religious satire addressing superstition and pseudoprophets the film stars an ensemble cast of Aamir Khan (as the title character), Anushka Sharma, Sushant Singh Rajput, Boman Irani, Saurabh Shukla and Sanjay Dutt.

After the success of 3 Idiots (2009), Hirani and Joshi began scripting their next project; finding similarities with the plot of Inception (2010), they scrapped the film.

The film's soundtrack was composed by Shantanu Moitra, Ajay–Atul and Ankit Tiwari with lyrics written by Swanand Kirkire, Amitabh Varma and Manoj Muntashir.

With a worldwide gross of ₹750.60–769.89 crore, it continues to be one of the most successful films in Indian cinema, reflecting its lasting popularity and cultural significance.

A nude humanoid alien lands on Earth on a research mission in Rajasthan, India, and is stranded when the remote control to summon his spaceship is stolen.

In Belgium, an Indian woman, Jagat "Jaggu" Janani Sahni, meets a Pakistani man, Sarfaraz Yousuf, and falls in love with him.

Her father objects to their relationship, citing their different religions, and consults their family astrologer, godman Tapasvi Maharaj, who predicts Sarfaraz will betray Jaggu.

Determined to prove them wrong, Jaggu asks Sarfaraz to marry her, only to be heartbroken after receiving an unsigned letter calling off their wedding and not to contact him.

She earns his trust by rescuing him when he attempts to take money from a temple's donation box as a "refund" for God's broken promises, and he opens up to her.

He learned Bhojpuri at a brothel by holding hands and exchanging memories with a prostitute and started looking for the thief who stole his remote in Delhi, where he earned the name "PK" (drunk) as people thought he was intoxicated when getting confused with different religions.

After Jaggu pranks an unknown caller in front of him, PK naively conjectures Tapasvi and his other godmen must be unintentionally dialing a "wrong number" to communicate with God, advising the public against engaging in meaningless rituals for their prayers.

Tapasvi claims he has a direct connection to "God", citing his prediction of Sarfaraz's betrayal to prove Muslims to be liars.

Eventually, they decided to scrap the film, then Hirani and Joshi reworked on the script, changing the entire tone and angle.

[13] In PK, Khan played nine avatars (costume changes)[14] and, during the course of the film, the actor had to chew over 10,000 betelnut preparations called paan.

[citation needed] Betelnut is a psychoactive stimulant used throughout Asia and characterised by its ability to stain users' mouths red.

[29] Firstpost compared PK to Hirani and Khan's previous collaboration 3 Idiots, as they both involve "A socially awkward and 'different' young man—who walks and talks in a strange, enthusiastic childlike manner—observes the system, questions it, asks you to look at the many ludicrous things that inform it, and eventually brings about a minor revolution.

"[30] In an interview, Rajkumar Hirani revealed that Iinitially, the plot involved the alien protagonist falling in love with a girl early on, which led him to question religious divisions when he encountered her father’s prejudice.

[52] Indiagames, a part of Disney India's Interactive business, announced the launch of the official mobile game 'PK' based on the film.

On 14 December 2014, Aamir Khan, Anushka Sharma, Rajkumar Hirani, Vidhu Vinod Chopra, Siddharth Roy Kapur, managing director of Disney India and Sameer Ganapathy, VP and head, Interactive of Disney India launched the game at the Reliance Digital Store in Juhu amidst much fanfare.

The gamer has to avoid a number of obstacles on the way, which include cows, buses, Delhi trains, rickshaws, traffic jams, and more.

[76] DNA reported, "Being the first film to use Rentrak, Khan has taken the first initiative to bring in a paradigm shift from the usual norms followed in Bollywood.

"[77] The soundtrack is composed by Shantanu Moitra, Ajay–Atul and Ankit Tiwari with lyrics written by Swanand Kirkire, Amitabh Varma and Manoj Muntashir.

[85] Rajeev Masand of CNN-IBN gave 3.5 stars quoting "It's a courageous film that sticks to Hirani's well-oiled formula".

[86] NDTV gave 5 stars calling it "PK is a winner all the way, a film that Raj Kapoor, Bimal Roy and Guru Dutt would have been proud of had they been alive.

[146][147] It became an instant hit, grossing US$5.14–5.3 million in first three days of release due to good word-of-mouth—a record for an Indian film (previously held by Dhoom 3), debuting at second place at the Chinese box office behind Avengers: Age of Ultron.

"[168][169] When the shoot was going on in Chandni Chowk area of Delhi, an FIR was lodged against the makers of the film for allegedly hurting religious sentiments in October 2013.

[170] The objection was regarding a scene where a man dressed as the Hindu deity Shiva, pulls the rickshaw with two burqa clad women as passengers.

[171] In July 2014, the film's poster sparked a controversy[vague] as it featured Aamir Khan posing almost nude with only a radio cassette recorder covering his genitals.

Subsequently, some theatres were vandalised by those activists,[175][176][177] who demanded a ban on the movie[178] and a Public Interest Litigation was filed against PK for the same.

[183] The Sunni clerics of the All India Muslim Personal Law Board demanded the removal of some scenes of the movie which they believed were hurting religious sentiments.