Since the onset of an incisional hernia is caused by the biological problem of forming stable scar tissue, the mesh techniques are now the methods of choice for incisional hernia repair. Polypropylene is the material most widely used for open mesh repair. New developments have led to low-weight, large-pore polypropylene prostheses, which have been adapted to the physiological requirements of the abdominal wall and permit a reliable tissue integration. These meshes make it possible for a scar net to form rather than a stiff scar plate, thus helping to avoid the complications encountered with the use of earlier meshes. The ideal position for the mesh seems to be the retromuscular underlay position, in which the force of abdominal pressure holds the prosthesis tightly against the deep surface of the muscles. The retromuscular underlay repair technique has yielded the lowest incidence rates for recurrence: around 10% even after long-term follow up. Analysis of the failures after open mesh repair suggests that inadequate size of the mesh with insufficient overlap at the edges is the main reason for recurrence. An overlap of at least 5-6 cm all round must therefore be considered mandatory for successful reinforcement of the abdominal wall. Open mesh repair, particularly with modern low-weight polypropylene meshes applied by the retromuscular underlay technique, offers excellent results in the treatment of incision hernias, even in long-term follow-up studies.