The fjord head at approximately is formed by the estuary of a river flowing from the glacial outflow lake in
Johan Dahl Land. At approximately , south of the
Narsarsuaq settlement, the fjord is joined by its tributary
Qooroq Fjord from the northeast, changing direction from southern into southwestern. Bounded by long peninsulas and low-lying islands from the southeast and the northwest, it has its mouth in the Skovfjord which empties in
Labrador Sea at approximately . The Narsaq Sound, between the peninsula forming the northern shore of Tunulliarfik Fjord and
Tuttutooq and
Illutaliq islands, connects with neighbouring
Bredefjord and
Nordre Sermilik to the north. == Settlement ==