Injection of acrylic material into the aneurysm is a relatively simple procedure if escape of the material into the circulation can be prevented by means of a coil inserted into the aneurysm prior to injection of the acrylic material. In the present study, polypropylene (00000) suture was given a coiling property. On extrusion through a 22 gauge spinal needle the suture regained its coiled shape. Experiments were carried out on dogs with the external carotid artery serving as a model for an aneurysm. Using a 22 gauge spinal needle, first the coiled suture was inserted into the aneurysm and then methylmethacrylate was injected. Ten aneurysms were thrombosed. None of the animals suffered a neurological deficit. Complete thrombosis of the aneurysms were noted in all the animals. On perfection, this technique could eventually be used for stereotaxic thrombosis of intracranial aneurysms.