Detecting motion-in-depth is more difficult than detecting equivalent lateral motion (e.g. Tyler, 1971). Because there is an early averaging of left and right motion signals, some work suggests the two monocular signals could effectively cancel out when an object moves only in depth (e.g. Harris, McKee, & Watamaniuk, 1998). In the literature on “flow-parsing” (Rushton & Warren, 2006), it has also been shown that an early subtraction of global components of motion from the retinal image isolate scene-relative object movement (Warren & Rushton, 2009). Here we examine the relationship between motion-in-depth and flow-parsing processes. Using a display with a probe object within an array of background objects, we first measured reaction times to detect the motion-in-depth of the probe in the presence of static background objects. As expected, reaction time was maximal when the movement of the probe was directly towards the observer (pure motion-in-depth). When the objects moved in a radial pattern on the opposing side of the screen, the trajectory that produced the maximal reaction time changed. This change was in line with a subtraction of global motion prior to the detection of motion-in-depth, suggesting an early contribution of global motion information to the perception of motion-in-depth.