The Queen Charlotte Basin region of the west coast of Canada has significant petroleum potential. Sedimentary basins within the region contain abundant reservoir strata, oil and gas source rocks, diverse trap types and numerous oil and gas shows. A quantitative assessment of petroleum potential in the Queen Charlotte Basin region provides estimates of total recoverable resources of 414 million m(3) (2.6 billion barrels) of oil and 565 billion m(3) (20 Tcf) of gas, at median values. The resource estimates are based on evaluations of three conceptual petroleum plays involving Cretaceous and Neogene sandstone and conglomerate reservoirs and Jurassic and/or Tertiary source rocks. The most prospective plays occur in Neogene strata within the Queen Charlotte Basin, beneath eastern Graham Island and in the offshore shelf areas of Dixon Entrance, Hecate Strait and Queen Charlotte Sound. While the assessment study provides a favourable geological basis for future petroleum exploration in the Queen Charlotte Basin region, the complex geology and anticipated risks associated with the petroleum plays suggest considerable amounts of new seismic surveying and exploratory drilling may be required to adequately evaluate the region＇s oil and gas potential.