-Post Doctoral Assistant, Department of Chemistry, University of Florida, Gainesville, Florida, U. S. A., in the research group of Kenan Professor Alan R. Katritzky FRSC, Oκτώβριος 1989 – Οκτώβριος 1990.
2.Visiting Professor, Department of Chemistry, Duke University, Durham, North Carolina, U. S. A., in the research group of Professor Steven W. Baldwin, Ιούλιος 1994 – Oκτώβριος 1994
3. Visiting Professor (στα πλαίσια του προγράμματος ανταλλαγής μελων ΔΕΠ του Υ.Ε.Π.Θ.–D. A. A. D.) Department of Chemistry, Leipzig University, Leipzig, Germany, in the research group of Professor Athanassios Giannis, 1-10 Ιουνίου 2005.
4. Visiting Professor (στα πλαίσια του προγράμματος ανταλλαγής μελων ΔΕΠ Ελλάδας-Πολωνίας)
i) Department of Heteroorganic Chemistry, Centre of Molecular and Macromolecular Studies, Polish Academy of Sciences, 90-363, Łódz, Poland and
ii)Institute of Chemistry, Environmental Protection and Biotechnology, Jan Długosz University in Częstochowa, 42-201 Częstochowa, Poland
in the research groups of Professor Piotr Balczewski, 16-25 Αυγούστου 2013.