A temporary seismograph network was operated in a seismically active region of northern Baffin Bay during part of September–October 1978. The array comprised three portable smoked-paper seismographs on Baffin Island and three ocean-bottom seismographs in Baffin Bay. During the experiment a number of earthquakes were recorded sufficiently well to be located by an iterative procedure. Two seismicity regimes are distinguished. The first is a narrow onshore zone of shallow (<10 km) earthquakes near and parallel to the coast. Most of this activity was concentrated in the Cape Jameson region of Baffin Island, with one earthquake of magnitude 3. A second, more diffuse group of events was offshore in Baffin Bay. These were deeper and indicated a possible trend normal to the coast. They may be associated with the fault plane of the 1933 magnitude 7.3 Baffin Bay earthquake. The seismicity results and the Baffin Island – Baffin Bay margin structure deduced from earthquake and explosion travel times are in agreement with previous studies.