A humanoid land naked on our planet in Rajasthan, an Indian state, while on a mission. But he losts his remote control, which is the only way he can communicate with the ones on his planet.
While in Bruges, Jagatjanani abbreviated Jaggu, meets a Pakistani Sarfaraz near a cinema hall. They both fall in love. Jaggus being a Hindu and Sarfaraz Muslim, her parents aren't happy with this relationship. He consults with a Tapasvi, who tells that he is a man of god, and is in direct touch with him.
Tapasvi tells that Jaggu will be betrayed by him. In order to prove them wrong, she decide to marry him. On the day she reaches the church, she gets a letter which says to cancel marriage due to differences in culture. She believes the letter to be of Sarfaraz's.
She comes back to India and becomes a reporter. She meets the lost alien who is didtributing the pamphlets reading Missing God. She then finds him stealing money from temple's box and helps him. Where she has to sacrifice her money.
She discovers more about the man, who is named PK by people. He tells that he is surviving by stealing clothes and money from dancing cars. They had no fashion sense of clothes due to which once he wore clothes of a woman. Sometimes, doctor, or police.
Bhairon, who hits him tells to go Delhi to find the locket. He goes to every place where god lives but he is rendered helpless. He coincidentally reaches to Tapasvi, but he denies saying that he owns him.
Jaggu promises to get it back and she leads a wrong number movement to expose tapasvi, which is a great hit. PK has a live TV conversation with Tapasvi, where he brings people of different religions in outfits of other religions. He tells them to identify them. But later reveals their true identity. tapasvi forcefully returns the remote.
Jaggu discovers that the letter wasn't from Sarfaraz and calls the Embassy in Belgium to find about him. He tells that he also read the letter in the church thinking that Jaggu left it and didn't call her. Finally they reconcile.
PK falls for Jaggu, collects all her memories in his bag, audio tapes with batteries. He lies when Jaggu gets to know about the audio tapes. Jaggu reads a letter he wrote for her and realized his love for herself.
PK return after an year, fora a research on human nature.