Elected Member of the Italian Parliament, she served as Vice President of the Committee on Foreign Affairs of the Chamber of Deputies for the entire XVIth legislature, ending in March 2013. She was also a member of the Italian delegation to the Council of Europe, where she represented Italy in the Network for the fight against violence on children. Nirenstein also established and chaired the Committee for the Inquiry into Antisemitism of the Italian Parliament. During her parliamentary activity, she had a particular focus on Israel, human rights, international controversies, democratization in the Middle East and awareness of Iran's nuclear capabilities.