In 2006, the following guests visited our institute: P. Ambroz (Astronomical Institute, Ondrejov, Czech Republic), M. Bárta (Astronomical Institute, Ondrejov, Czech Republic), P. Bellaire (NSF, North Arlington, Virginia, USA), G. Cevolani (ISAC (FISBAT) CNR, Bologna, Italy), H. Coffey (NOAA NGDC, USA), J. Chen (Naval Research Laboratory, Washington, DC, USA), L. Errico (ISAC (FISBAT) CNR, Bologna, Italy), D.A. Falconer (NASA MSFC, Huntsville, AL, USA), A. Grandpierre (Konkoly Observatory of the Hungarian Academy of Sciences, Budapest, Hungary), A. Hanslmeier (Institute of physics/IGAM, University of Graz, Graz, Austria), J. Janík (Institute of Theoretical Physics and Astrophysics, Masaryk University, Brno, Czech Republic), M. Jankovic (Central European University, Budapest, Hungary), M. Karlický (Astronomical Institute, Ondrejov, Czech Republic), J.M. Kreiner (Mt. Suhora Observatory, Cracow Pedagogical University, Krakow, Poland), D. Kudryavtsev (SAO RAN, Russia), Z. Mikulášek (Institute of Theoretical Physics and Astrophysics, Masaryk University, Brno, Czech Republic), M.I. Nouh (National Research Institute of Astronomy and Geophysics (NRIAG), Helwan, Cairo, Egypt), J. Pap (GEST/University of Maryland, Greenbelt, USA), I. Pustilnik (Tartu Observatory, Estonia), M. Planat (FEMTO-ST, LPMO/CNRS, Besancon, France), J.I. Romanjuk (SAO RAN, Russia), A.N. Saad (National Research Institute of Astronomy and Geophysics (NRIAG), Helwan, Cairo, Egypt), S. Shugarov (Sternberg Astronomical Institute, Moscow State University, Moscow, Russia), S. Stoiser (Institute of physics/IGAM, University of Graz, Graz, Austria), A. Veronig (Institute of physics/IGAM, University of Graz, Graz, Austria), A. Vittone (ISAC (FISBAT) CNR, Bologna, Italy), S.T. Wu (CSPAR, University of Alabama in Huntsville, Huntsville, USA) V. Yurchyshyn (Big Bear Solar Observatory, CA, USA).