Stainless steel wire, dia. 50 microns, was used as suturing material in rabbit corneas for periods of 1.5, 3 and 7 months respectively, in order to test its inertness and acceptance by the corneal tissue. One clinical case of stainless steel wire used for fixation of an I.O.L.-implantation, after a 5-year residence in the eye, is reported as well. After 1.5 months' residence, the suture margins were well covered with tissue containing irregularly shaped endothelial cells, some fibroblastic-type cells and various kinds of collagenous fibre material. The buckled surface was partly covered with a very thin membrane of collagenous material, strands of collagenous fibres and a few fibroblastic-type cells. After 3 months' residence the buckle was almost completely covered with an endothelial cell layer. The individual cells had a somewhat irregular hexagonal shape. At a few local sites closure was still progressing, with filopodia and other collagenous matter generated by neighbouring cells on top of previously deposited Descemet's membrane. After 7 months' residence, the buckle was completely covered with normal endothelium. The fixation suture in the human case showed perfect acceptance by the corneal tissue.