The authors studied the results of using polypropylene monothread as suture material in 254 patients who underwent planned and emergency operations for various diseases. It was found that polypropylene monothread used for suturing the skin, deeper located tissues, granulating wounds is sufficiently elastic, acapillary, strong, and biologically inert owing to which there is no need to remove it until complete healing of the wound even in considerable exposition. The monothread causes a less traumatizing effect than does a thread of natural silk when drawn through the tissues. A blue or green color of the monothread makes it visible during the operation.