On 27 May 2015 Kobus Oosterhoff passed away at the age of 82. Kobus was employed at the Mathematisch Centrum in Amsterdam from 1961 to 1969, at the Roman Catholic Univerity of Nijmegen from 1970 to 1974, and then as professor in Mathematical Statistics at the Vrije Universiteit Amsterdam from 1975 until his retirement in 1996. In this obituary Piet Groeneboom, Jan van Mill and Aad van der Vaart look back on his life and work.@en