AbstractIt was formerly supposed that the small island of Grímsey about 40 km north of the mainland of Iceland, had not been glacierized during the Würm period. Evidence for a glaciation is presented together with arguments for a Würm dating. The wastage pattern of the northerly flowing ice was influenced during the latter stages of deglaciation by the Skjálfandadjúp trough, east of Grímsey. This caused changes in the direction of ice movement and the formation of meltwater channels dipping to the south and south-west.