Two experiments are described which examine the effect of distance in the depth plane, as defined operationally by binocular disparity, on focused and divided attention. In both experiments, disparity was manipulated with a Tektronix stereoscopic 3D display system. In Experiment 1 (focused attention), 10 subjects classified letter stimuli presented at zero disparity. The targets were surrounded by two irrelevant stimuli. Results demonstrate a fairly 'narrow' attentional bandwidth in depth for focused attention. In Experiment 2 (divided attention), 8 subjects performed a one-axis pursuit tracking task at 0 disparity, while concurrently responding to stimuli presented immediately below, and at 5 different depth planes. Results here suggest that in divided attention, where stimulus location is known in advance, the attentional bandwidth in depth is sufficiently broad to accomodate the same range of depth planes over which filtering had been observed in focused attention. When, however, the depth plane was randomized and unpredictable, evidence for a depth gradient of divided attention was found. Results are discussed in terms of attentional theory and the usefulness of stereoscopic displays.