Ceramic hip joint heads are used in the field of endoprosthetics for more than 30 years. There are a lot of in vitro tests to determine the behaviour of these implants under body like conditions that means hip simulator testing etc. But it is accepted, that these tests can only reflect ideal conditions in vivo. Therefore it is necessary to examine also retrievals after different periods in vivo. Six explanted ceramic heads after times in vivo between 0.5 and 19 years were investigated concerning their geometrical dimensions and surface conditions.