Aquilani began his career with Italian side Roma and, after a brief loan spell at Triestina, returned to the Serie A club where he became a regular in the Roma side during the 2005–06 season, earning the nickname "Il Principino" (The Little Prince), due to his resemblance to former Roma legend Giuseppe Giannini, both in terms of appearance and playing style, who was known as "Il Principe" (The Prince). During the following season, he suffered a thigh injury and was ruled out for several months. In 2007 and 2008 he won consecutive Coppa Italia titles with Roma, as well as the 2007 Supercoppa Italiana.