Unprecedented numbers of Pectoral Sandpipers Calidris melanotos were reported in Britain & Ireland during autumn 2003, and to a lesser extent throughout the rest of Europe as well.This paper presents a review of the occurrence patterns and migratory behaviour of the species, both during the 2003 influx in Europe, and on a wider scale. Potential explanations for the unexpected regularity of this species in Europe, given its relatively small global population size and predominantly overland migration strategy, are discussed. It is suggested that the routes and wintering grounds used by Pectoral Sandpipers are more dynamic than was previously acknowledged.