The Eider is a widespread species on both the east and west coast of Sweden especially in the archipelagos. Large numbers of Eiders are also breeding in other Baltic countries. During the autumn, the Eiders leave the Swedish east coast as well as most other breeding areas in the Baltic gathering in the south-western part of the Baltic, in the Kattegat and in the North Sea.

The Eider is a common wintering bird along the Swedish west coast. At the last country-wide surwey in January 2004, no less than 36000 were counted in the province of Bohuslän to be compared with about 6000 at a similar survey in January 1971. In the southern par of the Swedish west coast and the province of Scania, about 9000 were counted in January 2004, whereas only small numbers winter in the Baltic proper. In 2009 a special survey found about 50000 wintering Eiders on the Swedish west coast, the number being only slightly larger than in 2004, but appreciably higher than during previous total counts in 1987 -89 and earlier. At the country-wide survey 2015 the total winter count along the west coast was also around 50000.

September indices showed the expected longterm decrease in the Eider, whereas the January indices showed an increasing trend. This applies both to the shorterm and longterm indices. In January, there are clear regional differences. Midwinter indices for the Baltic shows a decrease, whereas the marked increase in the national indices is related to an increase in the wintering population on the west coast.