Abstract: Disclosed herein is a device and method of use for a thoracic expander. More specifically, the present invention generally relates to a device and method of use for a horizontal thoracic expander, which allows for the creation of thoracic volume in a patient by expanding the thoracic cavity in the horizontal plane. In one embodiment the device is comprised of a housing element and at least one extending element. In another embodiment, the device is comprised of two opposing extending elements. In yet another embodiment, the opposing extending elements are also comprised of interchangeable attachment elements that are positioned on the distal ends of the extending elements. In yet another embodiment, the device is also comprised of a gear element, which is coupled to the extending elements and a control element allowing for the displacement of the extending arms in opposing horizontal directions.