Comparative morphology of the African ape hand is receiving renewed interest in the wake of recent discoveries of fossil hominid hands and the increasing number of biomolecular studies that question the traditional chimpanzee/gorilla clade. This paper compares ontogenetic sequences of Pan paniscus, Pan troglodytes troglodytes, Gorilla gorilla gorilla, Gorilla gorilla beringei and Pongo pygmaeus in order to assess whether or not previously established interspecific differences between adult chimpanzee and gorilla metacarpals and phalanges are due to a differential extension/truncation of a common growth allometry. Furthermore, inter-ray comparisons are made within the African apes to evaluate the functional role of individual rays. Results indicate that most dimensions of metacarpals and phalanges are ontogenetically scaled between Pan and Gorilla and also among pongids. Metacarpal and phalangeal lengths, however, depart from the general pattern of ontogenetic scaling. In interspecific comparisons of metacarpal and phalangeal lengths regressed on public lengths, the slopes are not significantly different between chimpanzees and gorillas, but there are significant transpositions in the growth trajectories such that Gorilla has shorter rays than Pan at common sizes. Inter-ray comparisons between genera reveal that gorillas have less variation between rays in almost all dimensions compared to chimpanzees. On the basis of these results, it is concluded that most differences in metacarpal, phalangeal, and inter-ray morphology between chimpanzees and gorillas that are not attributed to ontogenetic scaling may be related to the following: (1) kinematically distinct types of knuckle-walking, (2) a greater proportion of body weight borne on the hands of gorillas than chimpanzees at common sizes, or (3) a higher frequency of arboreal behavior of chimpanzees than gorillas at common sizes.