Abstract. – The present article explores the thesis that during World War I, an earlier unity between ethnography and physical anthropology increasingly dissolved and became disrupted. This thesis is examined through the case study of a research sojourn at the German POW camp of Wünsdorf, where Vienna anthropologist Rudolf Pöch and his collaborators were invited to pursue the kind of measurements and documentation which Poch had initiated during the war in Austrian POW camps. While Poch’s original research proposals and project plans for POW camps still had claimed to investigate some of the major, overarching problems of anthropology and ethnography, the researchers soon lost sight of those theoretical questions when their investigation produced such a wealth of data that processing them did completely absorb them. The technical aspect of growing specialization in data processing, however, went hand in hand with a gradual shift of methodological interest. By consequence, the ensuing new thrust upon methodological autonomy for physical anthropology facilitated a theoretical re-orientation for both fields as well. After the war, and after Poch’s early death, this eventually led by the late 1920’s to the establishment of separate university departments for physical anthropology and for Völkerkunde. Each of these two fields now followed theoretical premises that were difficult to reconcile, and that had little in common with the unified field of anthropology and ethnography that had existed in the pre-war years. [history of anthropology, physical anthropology, methodology, First World War, POW camps, anthropometrical measurements]