Magnetic anchoring devices are disclosed herein. Expandable devices that are inserted into the stomach of a patient are attached to its interior wall by magnetically coupling. Such expandable devices, like inflatable balloons, comprise at least one magnetic device, which may be a magnet, a magnetizable material, or a magnetic metal. The magnetic device may be positioned on the external or interior surface of the expandable device or may be integral thereto. The magnetic device is magnetically coupled to a magnetic anchor positioned on a surface of the stomach wall. In this way, the expandable devices are anchored to the stomach walls, preventing migration of the device to other areas of the body where they may become obstructions and pose health risks.