Here a listing of Hundertwasser stamps is given. As far as I know the list is complete.

• United Nations 09-12-1983 Human Rights 6 stamps:
  New York: Michel 438/439
  Vienna: Michel 36/37
  Geneva: Michel 117/118
• United Nations 1995 Social Summit 3 stamps**
  New York: Michel 680
  Vienna: Michel 179
  Geneva: Michel 262
• Austria 11-12-1975 1 stamp, Michel 1505
• Austria 06-04-1987 1 stamp, Michel 1876
• Austria 08-10-1993 1 stamp, Michel 2111
• France-Council of Europe 15-01-1994: 2 stamps showing the same motive as Austria 1993
  Michel 51/52
• Liechtenstein 07-06-1993 1 stamp, Michel 1060
• Luxemburg 06-03-1995 3 stamps, Michel 1360/1362
• Senegal 10-12-1979 3 stamps and 3 sheets**, Michel 705/707 + Block 34-36
• Cap Verde 1983 1 stamp without overprinting (original stamp which was never issued)**, Michel III
• Cap Verde 30-10-1985 1 stamp with overprinting and 3 sheets, Michel 496 + Block 7/9
• Cuba 29-07-1967 1 stamp (this stamp was not especially designed by Hundertwasser but shows one of his paintings)**

List supplied by Stefan Kiesewalter and William Scheckel.

The stamps marked with ** are not yet in my collection. Offers are welcome.