To evaluate absorbable materials for use for replacement of the diaphragm, we implanted materials in experimentally-created diaphragmatic defects in pigs. As a short-term absorbable material, bovine serosa (BS) was used. Its absorption was complete after 4-6 weeks. In a control group, the defect was repaired with a continuous running polypropylene suture. In two other groups the defect was closed with lyophilized dura (LD) and a modified transverse abdominal muscle flap according to Hecker, respectively. Physical studies (load capacity and elasticity) and histologic investigations were performed in one-half of the animals of each group after 3 and 6 months, respectively. Considering their physical properties, it could be shown that all materials tested are suitable for replacement of the diaphragm, but that BS best resembled native diaphragm. We conclude that short-term absorbable BS is suitable for replacement of the diaphragm in pigs.