Two sightings of the extremely rare North Pacific right whale Balaena glacialis were made during regular surface and aerial observations of the winter assembly of humpback whales Megaptera novaeangliae in Hawaiian waters. On March 25, 1979 a right whale was observed schooling with 8-9 humpback whales. On April 10, 1979 at a location approximately 122 km from the first sighting, a right whale was seen schooling with a single humpback whale. Markings, together with ancillary observations of others, suggest that the two sighting were of the same animal. At the first sighting, the right whale schooled closely with the humpbacks, surfacing and submerging synchronously with the other whales. At the second sighting, the humpback whale directed what appeared to be courtship behavior toward the right whale, including ventral display, rubbing the right whale with its long pectoral fin, and nudging the flanks and genital area with the head. The right whale ventrally presented on one occasion, but otherwise remained passive a few meters below the surface. The location of the wintering grounds of the North Pacific right whale have long been a mystery. Speculations from whalers’ records that Hawaii may have been a wintering ground are strengthened by these current sightings. The possibility that the superior humpback whales may have acoustically displaced the right whales in the Hawaiian breeding grounds is discussed.