The purge of Second World War collaborators in Belgium has not been the subject of many serious scientific research sofar. However, progress in theorizing and in data handling make it now possible to clear away the major impediments to such scientific research. After the war, extracts of the judgements of the military courts, which were responsible for the trial of collaborators, were published in the government gazette, « Het Belgisch Staatsblad ». These extracts provide the empirical basis of the project, which is put in the theoretical context known as « the ambivalence theory ». A brief look at the military judiciary system sheds some light on the processes behind the judging of collaborators. The article unveils some first results of the analysis of 5,000 court cases. The most important finding sofar is the absence of consistency - in time as well as in space - in the judging of collaborators in Belgium.