Tasiilaq is on the island of Ammassalik on the Eastern side of Greenland. A remote and isolated area, visitors here need to use helicopters to access the closest airport at Kulusuk. The inhabitants of East Greenland were living in isolation until visited here by an expedition led by Gustav Holm in 1884.

The Sermilik Station, dedicated to the research of the nearby Mittivakkat Glacier, is located near the town.

With 1,930 inhabitants as of 2010, Tasiilaq is one the fastest-growing towns in Greenland, with migrants from the smaller towns and settlements reinforcing the trend. Together with Nuuk, it is the only town in the Sermersooq municipality exhibiting stable growth patterns over the last two decades. The population increased by over 31 percent relative to the 1990 levels, and by over 13 percent relative to the 2000 levels.