I deal in this review with behavioral and developmental aspects of arm movementas imed at targets in immediate extrapersonal space. In addition, neural mechanisms that may subserve this function are discussed on the basis of neuronal recording and brain lesion studies. However, this is not a comprehensive review of each subject; thus, no exhaustive references are g~iven, nor is a detailed tracing of the history of ideas underlying modern studies attempted. These subjects can be found in specialized articles within each of the separate subfields considered above. Moreover, anatomical findings are not discussed. These as well as other topics related to certainaspects of cerebrocortical mechanisms subserving reaching movements were reviewed previously by Humphrey (1979).