The application relates to an intervertebral fusion implant for fusing two adjacent vertebrae, comprising a base piece (2), a cover piece (3), and an expansion device. The base piece (2) and the cover piece (3) are connected by an externally hinged rocker (4) that is located therebetween, and the expansion device is an expansion clamp (6, 6) on the rocker, a pushing device (5) being provided for the expansion clamp. The expansion clamp allows the rocker to be raised so that the implant expands vertically. Since the rocker is externally hinged, a large vertical travel path is available. Furthermore, the frictional forces of the expansion clamp prevent an unwanted return movement.
