| 1971 | Visiting Professor Harvard University, Boston, Mass-. USA |
| 1975 | Jacobson Visiting Professor, University of Newcastle upon Tyne, England |
| 1979 | Essex Visiting Professor, The Australasian College of Dermatologist |
| 1982 | Visiting Professor, Zwerling Memorial Lectureship, Harvard University, Medical School, Boston, Mass., USA |
| 1983 | Visiting Professor, Dohi Memorial Lecture, University of Tokyo, Japan |
| 1983 | Visiting Professor, Harvard University, Boston, Mass., USA |
| 1984 | Carl Truman Nelson Memorial Lecturer, Columbia University New York, New York, NY, USA |
| 1985 | Pillsbury Memorial Lecturer, University of Pennsylvania, Philadelphia, PA, USA |
| 1985 | Visiting Professor, The Skin and Cancer Foundation, Sydney, Australia |
| 1985 | Kung Sun Oh Memorial Lecturer, Yonsei University, Seoul, Korea |
| 1987 | von Zumbusch Memorial Lecturer, University of Munich, 1987 |
| 1988 | Visiting Professor and Distinguished Guest Lecturer, The Chinese Dermatological Association, Taipeh |
| 1990 | G. Rajka Visiting Professor, University of Oslo, Norway |
| 1991 | Marchionini Memorial Lecture, Marchionini Foundation, Hamburg, Germany |
| 1992 | Visiting Professor, Trinity College, Dublin |
| 1992 | 1st. St.John′s Hospital Dermatological Society Oration, University of London |
| 1992 | Cormane Lecture, ESDR |
| 1992 | Visiting Professor, the Australasian College of Dermatologists |
| 1992 | Kaposi Lecture, Szeged, Ungarn |
| 1994 | Erich Hoffmann Memorial Lecture, Bonn, Germany |
| 1996 | Heinrich Irenäus Quincke Memorial Lecture, Kiel, Germany |
| 1996 | First Otto Braun-Falco Honorary Lecture, Tübingen, Germany |
| 1996 | Austrian Academy of Sciences, Keynote Lecture |
| 1996 | University of Vienna, Faculty Lecture |
| 1998 | Udo Wile Lecture, University of Michigan, Ann Arbor, Michigan |
| 1998 | Hermann Pinkus Memorial Lecture, Pinkus Foundation, Wayne State University, Detroit, Michigan |
| 2001 | Guenter Goerz Lecture, ADF, Munich, Germany |
| 2002 | Clarence S. Livingood Lecture, AAD, 2002, New Orleans |
| 2002 | Hebra Lecture, Austrian Society of Dermatology and Venerology, Vienna |
| 2003 | Visiting Professor, Australasian College of Dermatologists, Sydney |
