Crustal extension during and immediately following continental collision is recognized as a fundamental process within many orogenic belts. In the North Atlantic region, Caledonian (Ordovician-Devonian) orogenesis resulted from continental collision of Laurentia and Baltica. In North-East Greenland (Laurentia), regional extension occurred during the Late Silurian to Early Devonian, probably as a response to crustal thickening at an earlier stage in the orogeny. Extension resulted in a crustal geometry analogous to that of a metamorphic core complex. Recognition of this process in North-East Greenland substantially increases the area of the Caledonides known to have been affected by such extension, and provides additional evidence that this Paleozoic collisional orogen evolved in a manner similar to Mesozoic and Cenozoic examples.