Chitin is an absorbable suture material with suitable mechanical properties. Tissue reaction is not specific and the good healing which ensued provided evidence for a satisfactory biocompatibility. Toxicity tests, including acute toxicity, pyrogenicity, mutagenicity were negative in all respects. The chitin suture was absorbed in about four months in rat muscles. The persistence of the tensile strength of the chitin was better than Dexon (TM) or catgut in bile, urine and pancreatic juice but weakening occurred early in the presence of gastric juice. Application in 132 patients proved satisfactory. Adverse effects were nil.