Existing packaging systems rely on human operation to position a box in the packaging device perform do the packaging task. Current facilities are not capable of handling boxes with different sizes in a flexible way. In order to improve the above-mentioned problems, an eye-to-hand visual servo automated packaging approach is proposed in this paper. The system employs two cameras to observe the box and the gripper mounted on the robotic manipulator to precisely control the manipulator to complete the packaging task. The system first employs two-camera vision to determine the box pose. With appropriate task encoding, a closed-loop visual servoing controller is designed to drive a manipulator to accomplish packaging tasks. The proposed approach can be used to complete automated packaging tasks in the case of uncertain location and size of the box. The system has been successfully validated by experimenting with an industrial robotic manipulator for postal box packaging.