A ♀ White-crowned mangabey Cercocebus atys lunulatus was born at Flamingo Land Zoo, Malton, UK, on 11 April 2005. On day of birth the infant was removed for hand-rearing after it sustained injuries from rough handling by its mother. The infant was hand-reared until 10 May when preliminary visual, olfactory, auditory and limited tactile contact was allowed with the adults. The infant continued to be hand-reared in full view of the adults until 15 June when the process of reintroduction was initiated. Full reintegration occurred on 15 July 2005. The processes used to hand-rear this infant White-crowned mangabey and successfully reintroduce it to its natal group are described in this paper.