This paper investigates the workspace of a three degree-of-freedom (DOF) compliant micro-motion stage with flexure hinges. This micro-motion stage has parallel structure for better stiffness and accuracy than serial structures and is driven by three PZT stack actuators. This kind of micro-motion stage can be used in applications including micro system assembly, biological cell manipulation and microsurgery. Nevertheless, workspace is fundamental. When selecting or designing micro-motion stage(s) for a particular application, its workspace must be studied to ensure the end-effector can reach the desired points with required orientations. In this paper the workspace of the presented micro-motion stage is investigated and presented, both mathematically and empirically.