Khandelwal made his Bollywood debut with Ronnie Screwvala's tight thriller Aamir (2008). He was cast as Dr. Aamir Ali, who returns to India from England and becomes the reluctant pawn of a terrorist group. Film critic Taran Adarsh from Bollywood Hungama reviewed "Rajeev Khandelwal is remarkable in the title role. The film would've fallen flat had it been entrusted to an inferior actor, but Rajeev lends the right shades and emerges triumphant. Watch him emote with his eyes in the latter reels mainly, and you realize that he knows the craft so well. An excellent debut!".CNN-IBN's Rajeev Masand added, "Uninhibited, spontaneous and blessed with unmistakable presence, Khandelwal holds the screen like a seasoned Artist. Using his face as a canvas to display emotions, he emerges as the biggest strength of this little film." The film grossed ₹18 million (US$280,000) domestically. For his work in the film, he received the nomination of Filmfare Award for Best Male Debut. In 2011, Khandelwal had two film releases. His first appearance was in the Bejoy Nambiar's thriller film Shaitan (2012) co-starring Kalki Koechlin. He played the role of Inspector Arvind Mathur, who is assigned by the Police Commissioner to solve a case unofficially, as he is on suspension after throwing a corporator from the first floor of his own house for allegedly beating up a woman. Taran Adarsh of entertainment portal of Bollywood Hungama wrote of his performance:"Rajeev Khandelwal, playing a cop who's fighting his inner demons, nails the role, giving a tight, focused performance".