This study, which was conducted on the Fosheim Peninsula, Ellesmere Island, North West Territories between 22 May and 15 August, 1974, documented habitat use, food preferences, activity, behavior and postures of Lepus arcticus. Observations of arctic hares along two 5-km transects throughout the snow free period, indicated that L. arcticus primarily used the foothills and higher slopes of the two major ridges in the study area. By observation, I determined that the main food of L. arcticus during the snow covered period was Salix arctica, and that large numbers of the flowers of forbes were consumed during the snow free period. The behavior of L_. arcticus changed significantly between the snow covered and snow free periods. Ten readily distinguisable postures and the conditions under which they are assumed were described.