His academic teaching experience spans in both undergraduate level at the University of Massachusetts and postgraduate level at the University of Connecticut and the University of Patras. 
His published work as co-author includes three books, six chapters in other authors' books, 92 scientific papers and 146 research presentations. Vasilis Gregoriou is also co-inventor of 15 patents. His research interests include flexible photovoltaic cells based on organic semiconductors, optically active materials based on conjugated oligomers, and nanostructured polymer materials. He has served as President of Society for Applied Spectroscopy (SAS) in 2001 and now he participates as National Representative of Greece in the Committee of the European Research Council (ERC) for the Horizon 2020 program, the Mari Sklodowska-Curie actions and the Future and Emerging Technologies (FET). Vasilis Gregoriou has been the Director of the National Hellenic Research Foundation since 2013. 
As a technology entrepreneur, Vasilis Gregoriou is the co-founder and the CEO of Advent Technologies which is based in Cambridge, Massachusetts. Advent Technologies develops advanced technology and devices in the field of energy and defense and it has also developed research collaborations with Northeastern University in Boston, US, Patras University in Greece, and the Institute of Chemical Engineering Sciences (ICE-HT/FORTH).