The population of Great White pelicans Pelecanus onocrotalus breeding in the Palaearctic (from Greece to the USSR) is estimated at more than 10 000 pairs. This species has, however, been very little studied and the restricted amount of ringing carried out on this bird has not greatly improved our knowledge of its migration routes and wintering areas. Counts have been carried out during the autumn migration period over several years at three different sites (Greece, Bulgaria and Israel) and the migration routes, the stopover sites and the numbers of birds can now be described with precision. By using a motorized glider, migrating pelicans could be followed from the north to the south of Israel in a single day, the average speed could be estimated and further information on the flight capabilities could be obtained. After the discovery of very high numbers during the migration period, the hypothesis has been advanced that non-breeding Great White pelicans do not remain on their wintering grounds, but return each spring to oversummer in the Palaearctic. The majority of the population of Great White pelicans breeding in the Palaearctic used to winter in the Nile delta (Egypt) at the start of this century. Because of the numerous developments carried out in the delta, however, they no longer winter there and they have been forced to find another wintering area further south. Unfortunately, this new site is still unknown and several hypotheses are proposed. Finally we recommend that movements be monitored by satellite in the future in order to discover the new wintering site(s) of this species and to confirm the correctness of the migration routes described in this study.