Based on the intensified survey efforts (since 2003) of Greenlandic breeding colonies of black-legged kittiwake (Rissa tridactyla), the total Greenland breeding population was estimated at roughly 110 000 breeding pairs, constituting about 4% of the total North Atlantic breeding population. This population estimate of black-legged kittiwake is the most reliable and updated estimate hitherto reported for Greenland. The results confirm considerable population declines in many areas of West Greenland. The breeding population of black-legged kittiwakes in the Qaanaaq area appears healthy, whereas the rest of the west coast has experienced declines, especially the north-western region (in the area from Upernavik to Kangaatsiaq). Exactly when these reductions have occurred is uncertain because of the limited survey effort in the past, but some colonies declined as far back as the mid-1900s, whereas declines of other colonies have occurred since the 1970–80s. East Greenland data from the past are few, but recent aerial surveys confirm that the abundance of breeding kittiwakes on this inaccessible coast is low. The reasons for the West Greenland declines are not documented. Poor feeding conditions and a high hunting pressure, particularly prior to 2002 when the open season was shortened considerably, are possible explanations.