Geologists from many countries have worked in Antarctica since the turn of the twentieth century and during the past thirty years the level of research activity on the continent has increased annually. As a result there has been a proliferation of stratigraphical names and lithostratigraphical schemes (Thomson, 1990). Furthermore, geologists from different nations are familiar with different standards and codes of nomenclature, which has resulted in a number of inconsistencies in Antarctic stratigraphical names. The SCAR Working Groups on Geology and Solid Earth Geophysics therefore recommended at their meeting in 1990 with SCAR XXII in São Paulo that, for sedimentary rocks, geologists working in Antarctica should adhere to the stratigraphical principles and recommendations proposed by Hedberg (1976). It was recognized, however, that igneous and metamorphic rocks present special problems of nomenclature. An ad hoc group of the SCAR Working Group on Geology for naming igneous and metamorphic rock units, constituted by the authors of this note, was therefore established to consider and discuss these problems and to formulate recommendations for suitable schemes that may be used internationally for Antarctica.