| August 2002-July 2003 | CERN Theory Division Associate, Marie-Curie Fellow (cat.40) |
| June 2001-September 2001 | CERN Theory Division corresponding Fellow |
| September 1999- today | NCSR `Democritos', Senior Researcher |
| June 1998- September 1998 | CERN Theory Division corresponding Fellow |
| May 1996-August 1999 | NCSR `Democritos', Researcher |
| May 1994- April 1996 | Research Associate, Physics Department, Durham University, United Kingdom, EU Fellow and unpaid Associate, Theory Division, CERN |
| March 1992- April 1994 | Fellow at CERN Theory Division |
| June 1989- February 1992 | Post-doctoral position in NCSR 'Democritos',Athens |
| November 1985- May 1989 | Teaching assistant in University of Athens |