Doucas received a Bachelor of Arts in Biochemistry from the University of Patras in 1987. A year later he was given a Master of Science degree in Biology from Pierre and Marie Curie University. Also in 1993, Vassilis earned his Doctor of Philosophy degree in Molecular and Cell Biology from Pasteur Institute.
Doucas began his career as a research assistant at National Center for Scientific Research of Molecular Genetics Center in 1987. A year later he took a position of a research associate at Pasteur Institute. Then in 1993, Vassilis became a postdoctoral fellow at Salk Institute for Biological Studies and held it for four years.
Also he worked as an assistant professor at the University of Geneva Medical School from 1998 to 2001. In addition, Vassilis was a visiting scientist at Salk Institute for Biological Studies in 1998-2000.
In 2002, Doucas served as a senior scientist at National Center for Scientific Research of College-de-France and held the position until 2004. Since 2005 he has been an investigator and research director at Virtual Molecular Chorobiology Laboratory.
In 2007, he held the position of a visiting investigator at Lawrence Berkeley National Laboratory.
On September 21, 1992 Vassilis Doucas married Cecile Fougeron. They have a child.