Born in Bucharest, Creţu graduated from the Academy of Economic Studies' Faculty of Cybernetics (1989), and worked as an economist for factories in Blaj and Bucharest until 1990. After the latter date, she was employed as a commentator on current events by the newspapers Azi, Curierul Naţional, and Cronica Română. She worked for President Iliescu's Spokesperson Office during two separate mandates (in 1992-1996 and in 2000-2004); between 2000 and 2004, Creţu was Presidential Advisor (with the rank of Minister), Presidential Spokesperson and Head of the Public Communication Department. In 2002, she was also selected by President Iliescu for the Board of the Romanian Television Company, and confirmed by a vote in Parliament.
As a Senator, she sat on the Foreign Policy Committee, and was a full member of the Romanian Delegation to the Parliamentary Assembly of the OSCE. In January 2005, she was invited to Amman, Jordan, where she conducted a training seminar for appointees to spokesperson positions in Iraq.