Minced non adsorbable or adsorbable suture threads introduced into peritoneal cavity of guinea pigs elicit at inflammation with mononuclear and giant cells surrounding suture thread fragments. We studied the presence in the peritoneal cavity of chemotactic factors for PMN cells and we compared the results in relation to the different type of the suture threads used (Dexon, Mersilene, Gore-Tex). The peritoneal cavity was washed, the fluids collected and used as chemotactic agents. The chemotactic response was assayed by employing multiwell chemotaxis chambers (Neuro Probe) and PMNs from normal, non-treated guinea pigs. Quantification of the migration was calculate by chemotactic index (A/B) (B = random migration, A = chemotaxis). The results demonstrate that a chemotactic activity is present in peritoneal fluids following the inflammatory process. This activity is evident at 7th day after Dexon and Mersilene inoculation; using PTFE however, it decreases at 14th d, when the inflammatory process is already developing into healing tissue. In conclusion the chronic inflammation determines the appearance of chemotactic factors for PMN cells; it is suggested that reactive, mononuclear cells, involved in the process, could be responsible for their production and release.