Migrating birds are known to avoid topographical barriers. At these barriers, the local environmental conditions often lead to a high concentration of migrants at certain corridors or points usually referred to as ‘bottlenecks’. The Greater Caucasus and the Caspian Sea are such barriers for migrating birds in south-western Asia. A narrow coastal plain between the Greater Caucasus and the Caspian Sea in Azerbaijan (Besh Barmag bottleneck) provides excellent conditions for studying bird migration of a poorly known region. Here, surveys were carried out in autumn 2011 and spring 2012 to count raptor, passerine and waterbird migration from three different observation points. Data for fixed block of six hours continual observations together with random counting hours have been interpolated by a special calculation to obtain estimated grand totals per species. In total, 278 bird species were recorded, eight of which are red-listed as globally threatened by the IUCN (i.e. Sociable Lapwing Vanellus gregarius, White-headed Duck Oxyura leucocephala, Saker Falcon Falco cherrug, Egyptian Vulture Neophron percnopterus, Lesser White-fronted Goose Anser erythropus, Dalmatian Pelican Pelecanus crispus, Eastern Imperial Eagle Aquila heliaca, Greater Spotted Eagle Aquila clanga), another eight as ‘near threatened’. Calculations indicated 1.24–1.51 million visible migrants in autumn 2011 and 0.65–0.82 million in spring 2012. For four species (Eurasian Skylark Alauda arvensis, Common Starling Sturnus vulgaris, Rosy Starling Sturnus roseus, Little Bustard Tetrax tetrax), the mean passage estimates exceeded 100,000 individuals. 15 species meet or are well within the range of the criterion of 1% of the world population. For a further 19 species they exceed the criterion of 1% of the flyway population. Dalmatian Pelican and Little Bustard were observed in great numbers representing 33–57% and 41–48% of the world population, respectively. Both species and, additionally, raptor and waterbird migration are discussed. The results presented here serve to underline the importance of Azerbaijan for migrating bird species in general, and to highlight in particular the great potential of the study area as a location for long-term monitoring studies in a remote and little-studied region.