The breeding range of Barrow's Goldeneye (Bucephala islandica) is largely restricted to northwestern North America, and little is known of the small population that winters in eastern Canada. Based on weak evidence, this eastern population was thought to nest mainly in northern Labrador. Our May 1990 to 1998 surveys identified a breeding area in the forest regions of the Quebec Laurentian Highlands. We observed Barrow's Goldeneyes on 137 lakes and 5 rivers, of which 95.2% were along the north shore of the St. Lawrence estuary and gulf. The species was found mainly on small lakes (≤ 10 ha) at greater than 500 m elevation. Most occupied lakes (96.5%) were within 100 km of the St. Lawrence River and 48.9% of them were headwater lakes. Four broods observed in 1998 represent the first eastern North American documentation of breeding. By means of satellite telemetry, 5 of 7 males captured on the wintering grounds were relocated on the north shore of the St. Lawrence River in May, 60–140 km inland from the estuary and gulf. Each male spent 34–50 days at its respective site, presumably with a mate. The north shore of the estuary and gulf may be the core breeding area for Barrow's Goldeneyes wintering along the St. Lawrence River.