Prior to her appointment as Puisne Justice of the Supreme Court of Sri Lanka, in 2012, she served as Solicitor General and Attorney General of Sri Lanka.

She made history when she became the first woman Senior State Counsel, the first woman Deputy Solicitor General, the first woman Additional Solicitor General and the first woman Solicitor General and first ever woman Attorney General of Sri Lanka. Eva Wanasundera served as Acting Attorney General 16 times before her appointment as Attorney General. She also represented Sri Lanka at key conferences abroad.