Grey was named chief executive officer of Paramount Pictures Corporation in 2005. In his position, Grey was responsible for overseeing all feature film development and production for films distributed by Paramount Pictures Corporation including Paramount Pictures, Paramount Vantage, Paramount Classics, Paramount Insurge, MTV Films and Nickelodeon Movies. He was also responsible for the worldwide business operations for Paramount Pictures International, Paramount Famous Productions, Paramount Home Media Distribution, Paramount Animation, Studio Group and Worldwide Television Distribution.
After arriving at Paramount in 2005, Chairman and CEO Grey was credited with leading a return to fortune at the box office. He oversaw the creation and revitalization of several major franchises, Transformers: Revenge of the Fallen, Star Trek, and Paranormal Activity, which was made for $15,000 and generated $192 million at the global box office. Paranormal Activity 2 grossed $177 million worldwide, and the third installment in the franchise collected $205.7 million worldwide in 2011. A fourth installment was released in October 2012. The studio's 2011 results included Transformers: Dark of the Moon, which grossed more than $1.1 billion worldwide, and Mission: Impossible – Ghost Protocol, whose $694 million global box office tally makes it the most successful entry in that franchise. Paramount's 2012 slate included The Dictator which earned $179 million on a $65 million budget.