The purpose of this study was to compare the frontal sinus size of ancient Greenlandic Inuit with ancient Inuit of Alaska and Canada, and to compare sinus size between ancient and modem Greenlandic Inuit. Also, it was analyzed whether cranial size was a determinant of frontal sinus size. Frontal sinus size was evaluated in terms of absence frequency and planimetrically. Absence was defined as a frontal sinus not exceeding a line drawn between the supraorbital rims. A significant increase in absence frequency was noted from Alaska over Canada to Greenland (males: p < 0.03; females p < 0.0001). This is in accordance with earlier studies, indicating that although these Inuit populations once have been commonly related to the Old Bering Sea population, the Greenland Inuit represent an endpoint in an eastward migration. There was a significant increase (p < 0.0001) in frontal sinus size from ancient to modern Greenlandic Inuit, probably indicative of a high degree of admixture with non-lnuit after modern colonization. The results regarding craniofacial size parameters and frontal sinus side were inconclusive. No single craniofacial variable showed significant effect on frontal sinus size, but the area displayed sexual dimorphism, females having smaller frontal sinuses.