Behavior in a confined group of mandrills (Mandrillus sphinx) was compared before and after their move from a traditional, all indoor exhibit to an indoor/ outdoor facility. The outdoor exhibit was designed to represent as well as is possible important features of the mandrills' forest habitat. We predicted that activity budgets in the outdoor exhibit would more closely resemble those of wild African Cercopithecines, specifically that time spent in forage/feed, locomotion, and social behavior would increase and time spent stationary would decrease. Time spent in forage/feed, locomotion, and stationary did change, as expected. However, there was a small significant decrease in some social behaviors. Differences in proximate environmental contingencies may explain the behavioral changes observed: feeding/foraging opportunities throughout the time on exhibit; increased social refuges; modest increase in facility size; and significantly increased environmental complexity and novelty. Our results are discussed within the context of data obtained from mandrills and baboons observed along a theoretical continuum between confined and free-ranging environments. This analysis supports what others have suggested: that primate well-being is not so much a function of confinement as of the presence of relevant incentives to engage in species-appropriate behavior.