Narsaq is served by Narsaq Heliport (IATA: JNS), with helicopter connections to Narsarsuaq and other settlements in South Greenland operated by Air Greenland. The helicopter schedule is infrequent and subject to weather; book well in advance, especially in summer.
The alternative is the boat service (dinghy or larger ferry) connecting settlements along the Tunulliarfik Fjord. This is the more atmospheric way to arrive and connects Narsaq to Narsarsuaq (which has the nearest airport with connections to Copenhagen and Reykjavik) and to Qaqortoq, the largest town in South Greenland.
There are no roads connecting Narsaq to other settlements.