Most studies of animals' home-range sizes have focused on adults, and the home ranges of subadults are usually, at best, only mentioned anecdotally. In this paper we report home-range sizes of 56 philopatric sexually immature (1.5- and 2.5-year-old) brown bears (Ursus arctos) in 2 Swedish study areas and how size is influenced by sex, age, body size, food availability, and population density. Home-range size was larger in males than in females, and home-range size increased with increasing body size, but was not related to individual age. Home-range size decreased with increasing population density, but less so in females than in males, a result consistent with the formation of matrilinear assemblages recently reported in brown bears. Although home ranges were larger in the less-productive northern study area than in the southern one, home-range size was not related to a general index of food availability.