• Composer : Pritam Chakravarty
• Lyricist : Amitabh Bhattacharya
• Singer : Arijit Singh

The film begins with the interview of Ayan Sanger, a singer who has newly acquired fame with his non-filmy songs. He tells the story of his experience of love in a flashback. A few years ago, in London, a chance meeting in a disco between Ayan and Alizeh happens and they hook up with each other. They get to know about each other and become friends. Later, when they discover their respective partners are cheating on them, they break up with their lovers: Ayan with Lisa D'Souza and Alizeh with "Dr." Faisal Khan and the two go to Paris to spend a week together. While Aayan falls in love with Alizeh but does not tell her while she considers him to be only a "friend". One day, Alizeh stumbles upon DJ Ali, her ex-boyfriend/lover, who wants to reconcile. Partially confused, but still in love with him, Alizeh decides to go with DJ Ali, and so unintentionally stops hanging out with Ayan and they cease communication. A few days later, Alizeh calls and invites Ayan to her wedding with DJ Ali Khan in Lucknow. Ayan is shaken on hearing this but reluctantly agrees to the invitation. At the wedding, he tells Alizeh he loves her but she rejects his feelings causing Ayan to leave the ceremony heartbroken. At the airport to board a flight to Dubai, he meets Saba Taliyar Khan, a poet, who is leaving for Vienna. She consoles Ayan and gives him a book with her poetry and number on it. Ayan reads that poetry and is moved by it. He calls her after three months stating that he is in Vienna and wants to meet her. They meet. He learns that Saba is divorced and has no place for love in her heart. They get into a relationship. Later, at an art gallery, he meets Saba's ex-husband, Tahir Taliyar Khan, who tells him that one-sided love is not a weakness but rather empowering as it isn't shared as one doesn't even need the presence of the person one is in love with to keep loving them regardless. Ayan, being who had blocked Alizeh from contacting him in all ways, finally calls and reconnects with her on being inspired by these words. Alizeh feels really happy and tells him that she missed their friendship. He begins to send pictures of Saba to her to try and induce jealousy while Alizeh tells him about her happy life with Ali and assumes that he has moved on. After a few days, Alizeh informs Ayan that she's coming to Vienna and wants to meet him. Ayan invites her for dinner with Saba to provoke Alizeh and make her feel jealous which Saba notices. Before she leaves, Ayan confronts her that she has no feelings and is heartless. They have a verbal fight and then he walks away. He goes to Saba, who hugs Ayan one last time and tells him that she really started loving him and that before it gets more intense, they should part their ways. She fears that she will get hurt realizing that she will never get the love she saw in Ayan's eyes for Alizeh. Their relationship ends and Ayan leaves. Ayan continues to harbour love for Alizeh and becomes a famous singer with his channel. He meets Ali one day and realizes that Ali and Alizeh are no longer together. Ali tells Ayan that even though Alizeh loved him, she wasn't able to get the love she thought she deserved. Ayan, concerned, goes to Alizeh's favourite spot and waits for two days there, hoping that she'll arrive. Alizeh meets him there and tells Ayan that she is diagnosed with stage four cancer and will not live much longer. Ayan is heartbroken but they try to make the best of their time together. Ayan tries to make Alizeh love him, to no avail. This leads to a fight between the two, and Alizeh decides to leave Ayan as he cannot understand that she can't fake her feelings for Ayan just to make him feel happy. Next morning Ayan tries to search for Alizeh, apparently reaching the airport and thus fulfilling her last wish also before death. Eventually, Ayan makes peace with the fact that he and Alizeh can at least be friends and nothing more. Alizeh dies soon. The screen blacks out and comes back to the present where Ayan, still a popular singer, is giving an interview based on the love of his life. Ayan sings the song "Channa Mereya", which is inspired by his one-sided love story, and finishes the interview.

• Track 1 : Ae Dil Hai Mushkil(Title Song) ( ऐ दिल है मुश्किल (शीर्षक गीत) )
• Track 3 : Bulleya ( बुल्लेया )
• Track 4 : The Breakup Song ( ब्रेकअप सॉन्ग )
• Track 5 : Cutie Pie ( प्यारी )
• Track 6 : Aaj Jane Ki Zid Na Karo ( आज जाने की ज़िद ना करो )
• Track 7 : Alizeh ( अलीज़ेह )