Abstract: Studies in leaf anatomy of 25 Ficus species in Nigeria have been undertaken to unravel the relationship among the species with a view to providing a set of stable taxonomic characters. Anatomy of the lamina and midrib featured characters that are described in detail for the first time in the Ficus species of Nigeria thus providing the basis for infra-generic classification of the genus. These are multiple epidermis, two or more-layered hypodermis, one to three layers of palisade parenchyma as well as the pattern of vascular system all of which contribute to further delimitation of the genus. Heavy lignification, multiple epidermis and the presence of hypodermis in some species such as F. abutilifolia, F. platyphylla and F. elasticoides were probable anatomical features of adaptation to xerophytic environments.