The myosin-V family is the most extensively studied of the unconventional myosin families. Most organisms examined have at least one member of the myosin-V family: many have multiple members. The wide range of species in which myosin-V has been identified suggests that myosin-V is a fundamental component of organelle transport in all higher eukaryotes. Possible cargoes for myosin-V range from melanosomes and synaptic vesicles in mammals to vacuoles and messenger RNA in yeast. In this review, we discuss the current state of research on the cellular function of myosin-V as described by the actions of the head, neck and tail domains.