A high-pressure sealing arrangement is provided for sealing a gap (26) between two concentric machine parts (4, 5) which can be moved relative to each other, of which a first machine part (4) comprises a groove (3) and a second machine part (5) comprises an outer peripheral surface (7) opposite the groove (3). A sealing ring (1) of an extrusion-resistant material and a tensioning ring (2) of an elastomeric material are provided in the groove (3). A shaped section of the sealing ring (1) on the low-pressure side can be deflected towards the outer peripheral surface (7) under fluid pressure load. When the pressure decreases, the pressure-dependent deflection of the sealing ring (1) automatically returns towards the initial, unpressurized state of the sealing ring (1). The sealing ring (1), viewed in cross-section and in the unpressurized state, has a shaped sealing ring surface (6) facing the outer peripheral surface (7), which merges at least with respect to the shaped section on the low-pressure side, into a shoulder surface (13) separated from the outer peripheral surface (7) at a first separation d.sub.1, which merges into a shoulder surface (13) side surface (20) with a second, larger separation d.sub.2 from the outer peripheral surface (7).