Abdomino-vaginal sling operations are favoured for the treatment of female stress incontinence recidive. An actual material for the sling ribbon is the Lyodura-soft. Histological reactions between one week and one year are described after experimental subcutaneous implantation of the Lyodura-soft ribbon in rats. After the initial inflammatory reaction in the surrounding connective tissue of the graft during the first 1-2 weeks, a capsule of fibre rich connective tissue is produced by the organism. After 6 months to 1 year the capsule has almost vanished. A reduction of the graft has not taken place during that time. The graft has not lost its morphological identity. Graft versus host reactions are not seen. According to our results the exact position of the ribbon has to be emphasized. The connective tissue of the organism has only a transitory effect on the stability of the graft and so on the success of the operation.