The film was shot in reverse as the crew didn't want to break the continuity of Ranbir Kapoor's hairstyle. So the climax with long hair was shot first.
Ranbir Kapoor had to take many efforts to transform himself into a rock star. He practiced guitar at A. R. Rahman's studio for many days, read Kurt Cobain's biography and familiarized himself with him.
Director Imtiaz Ali, who loved Kareena Kapoor's performance in his Jab We Met wanted to cast her in Rockstar. However, the script in Rockstar required some romantic scenes between the romantic leads. As Ranbir and Kareena happened to be cousins, this would have been a problem. She was replaced by Nargis Fakhri.
Major parts of the song "Saadda Haq" video was shot at the Norbulingka monastery in McLeod Ganj, Dharamsala. People waving the Free Tibet flag in the backdrop was shown in the song video. This triggered a dispute between Central Board of Film Certification and Imtiaz Ali when the Board ordered Ali to blur the flag and free Tibet slogan before the film hit the theatre, but the director refused to do it.
During the Sadda Haq sequence several scenes show Tibetans and Jordan performing in front of them. Several posters have 'give us our rights' written on them. The song literally means the same. This is an indirect support of the Tibetan cause of freedom from China from Imtiaz Ali. He has also stated that his next movie would be directly based on the same. Though the posters directly showing the word 'Tibet', it was blurred in the theatrical version.