She was born on December 9, 1972 in Leninakan (now Gyumri).

In 1989 she finished the Leninakan school #1.

In 1989-1994 she studied at the Law faculty of the Yerevan State University and graduated from it with excellence.

In 1994-1997 she attended a post-graduate course at the Yerevan State University. In 1997 she defended her thesis “Legal State: General Description, Principles of Organizing and Directions of Activity” and received a title of candidate of Legal Sciences. From 1994 till now she teaches.

She is an author of three works and more than a dozen of scientific articles.

In 2003 Arevik Petrosyan was awarded the scientific title of the Docent of Legal Sciences.

In 1994-1999 she worked in the staff of the President of the Republic of Armenia.

In 1999-2002 she worked as Deputy Minister of Justice of the Republic of Armenia.

She has a title of state councilor of justice of third class.

In 2002, according to the decree of the RA President, she has been appointed as a deputy Chairperson of the Council of Civil Service with a term of 5 years, and on January 15, 2007 – with a term of 6 years.

On May 12, 2007 she was elected as a deputy of the National Assembly by the proportional system from the "Prosperous Armenia" Party.

On June 7, 2007 she was elected as Chairwoman of the NA Standing Committee on Protection of Human Rights and Public Affairs.  On  November 12, 2007 she was elected Vice President of the National Assembly, on October 7, 2010 she resigned.

She has one daughter.