Factors influencing patterns of space use by pygmy rabbits (Brachylagus idahoensis) are poorly understood. We studied diurnal space use by adult pygmy rabbits during multiple breeding and nonbreeding seasons at 3 sites in the Lemhi Valley, Idaho, USA, during 2004–2005. Pygmy rabbits used larger areas than predicted by allometric models and documented by some previous investigations. Sex and season strongly influenced space use by rabbits. Males used larger home ranges and core areas, more burrow systems, and more widely dispersed burrow systems than did female rabbits. We also documented significant differences among study sites in many movement parameters, which suggested that local resource distribution also might influence how pygmy rabbits use space. Our results indicated that pygmy rabbits use large areas and exhibit seasonal, sex, and site-specific variation in patterns of movement and space use. Therefore, larger areas of habitat may be needed to conserve pygmy rabbits to accommodate seasonal, regional, and potentially annual variation in resource availability and to maintain linkages among populations.