After World War II< polymers, such as nylon, polyester, and polyolefin, replaced silk in nonabsorbent sutures. Polyglycolic acid, polylactic acid, and polydioxanone replaced catgut or regenerated collagen in absorbent sutures. Bioabsorbency, particularly for internal suturing, is optimal because permanent sutures can act as foreign bodies, eliciting various physiological reactions. Important suture properties are retention of tensile strength during healing, knottability and knot security, sterilizability, inertness, and rapid and predictable degradation and absorption. The two types of sutures are monofilament and braided multifilament. The major disadvantage of monofilament is its stiffness, which impairs knottability and knot security. Braided multifilaments are more flexible, but have a rougher surface, which can cause trauma, and have a greater tendency to break. A review of advances in suture technology focuses on the work of Sumitomo Electrical Industries, american Dyanamid, Ethicon, Japan Medical Supply Company, Surgical Corporation, Cobra Machinery, Nippon Kayaku KK, Spire Corporation, Mountain Medical Specialty Corporation, and Cornell University.