At any moment the visual system is inundated with information received by the eyes. Only a fraction of this information appears to reach visual awareness. This process of selection is one of the functions ascribed to visual attention. While many studies have investigated the role of attention in shaping neuronal representations in visual cortical areas, few have focused on attentional modulation of neuronal signals related to visual motion. We report here that the responses of direction-selective neurons in monkey visual cortex are greatly influenced by attention and that this modulation is present as early as the level of area MT. This finding demonstrates a stronger and earlier influence of attention on motion processing along the dorsal visual pathway than previously recognized.