The fjord head at approximately 61°14′40″N 45°30′35″W / 61.24444°N 45.50972°W / 61.24444; -45.50972 is formed by the estuary of a river flowing from the glacial outflow lake in Johan Dahl Land.

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 60°41′N 46°44′W / 60.683°N 46.733°W / 60.683; -46.733.

[1] 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.

Narsaq is a port of call for the Arctic Umiaq Line coastal ship in the summer season.

[3] The southbound ferry route backtracks from Qaqortoq until the mouth of Tunulliarfik, to then sail northeast alongside the lower part of the fjord, anchoring at Narsaq port before turning around the same day.