In the southeast, it was bordered by the Sermersooq municipality, however this border ran north–south (45° West meridian) through the center of the Greenland ice sheet (Greenlandic: Sermersuaq), and as such was free of traffic.

The coastline of northeastern Baffin Bay is dotted with islands of the Upernavik Archipelago, which was entirely contained within the municipality.

In the far northwest near Qaanaaq and Siorapaluk, the municipal shores extended into Nares Strait, which separates Greenland from Ellesmere Island.

Denmark claimed Hans Island as part of Qaasuitsup (now Avannaata), while Canada considers it to be part of the Nunavut region of Qikiqtaaluk.

Kalaallisut, the West Greenlandic dialect, is spoken in the towns and settlements of the western and northwestern coasts.