The considerable diversity of locomotor behavior within the suborder Prosimii largely is due to differences in locomotion between families. Within families, locomotion is relatively homogeneous, although some species, such as Otolemur crassicaudatus among the galagids and Hapalemur simus and Lepilemur spp. among the lemurids, differ from other species in their family. This paper describes the locomotion of a captive colony of red-bellied lemurs, Eulemur rubriventer (following the classification of Simons and Rumpler  who place all species of Lemur other than Lemur catta in the genus Eulemur), another species whose movements differ markedly from other members of its family, the Lemuridae. Features that distinguish the locomotion of E. rubriventer from other lemurids are the high frequency of leaping, low frequency of climbing and suspension, and the use of head-downward vertical climbing in this species. Leaping is the most common form of locomotion in E. rubriventer. Horizontal, rather than vertical supports, are preferred during leaping. Although the frequency of climbing in this study is relatively low, the large brachioradialis flange, robust hallux, and claw-like nails of E. rubriventer suggest that clinging and climbing on large diameter vertical supports (lacking in the enclosures used in this study) may be an important component of locomotion in wild E. rubriventer and may reflect a gummivorous or insectivorous dietary adaptation. While the locomotion of E. rubriventer differs from all prosimians yet studied, the general pattern of locomotor behavior seen in this species is most similar to other species of the family Lemuridae.