Member of the European Parliament
In 2005 she became Federal President of the Youth of Margherita and then in 2007 she was appointed National Head of Youth in the National Secretariat of the Democratic Party. From 2008 to 2014, she was MP for the Democratic Party. On 9 December 2013 she became a member of the National Secretariat headed by Secretary Matteo Renzi. Picierno had the role of National Head of Legality and South. On 28 January 2022, she was elected from among the 14 Vice-Presidents of the European Parliament.