In the 1980s, he headed the northern command of the Israel Border Police, and led rescue operations during the two Tyre catastrophes. He continued to rise through the ranks, and in 1993 he was promoted to Major General and appointed commander of the Border Police. He later served as a representative of the Israel Police in the Americas for two years. In 1998 was appointed head of police in the West Bank, and became head of the Southern District police in 2001. From 2002 to 2004 he was deputy police commissioner. In 2004, he left the police, and served as director-general of the Dan Bus Company from 2004 to 2005.
In 2006, he was elected to the Knesset on Yisrael Beiteinu's list. In March 2007, he was appointed Minister of Tourism, but his tenure ended in January 2008 when the party left the coalition. He retained his seat in the 2009 elections, for which he was placed fourth on the party's list. Upon the formation of the Netanyahu government on 31 March 2009, he was appointed Minister of Public Security.
On 16 June 2009, Aharonovich attracted controversy over a comment he made during a meeting with an undercover police detective in Tel Aviv's Central Bus Station. After the detective apologized for being untidy while meeting Aharonovich, Aharonovich replied that he looked as dirty as an “Araboosh” a Hebrew slur roughly translating as “little Arab”. He was denounced by several members of the Knesset as a racist following that, and subsequently apologized.