Despite impressive demonstrations of human infants' intersensory capabilities over the past several decades, there has been little focus on the contributions of prenatal and postnatal experience or the specific developmental processes underlying the emergence of intersensory functioning. Research with nonhuman animals has, however, provided a number of advances in understanding early intersensory perception. The authors explore the value of a comparative, convergent-operations approach to the study of early intersensory perception and examine how this approach has highlighted the study of (a) prenatal factors, (b) brain-behavior relations, and (c) context and experience variables contributing to infants' intersensory responsiveness. Examples of how human and animal research programs can cross-fertilize one another in their attempts to understand developmental processes underlying intersensory perception are considered.