This study evaluated the in vitro leukocyte response to titanium implants in the presence of autologous or heterologous antimicrobial peptides extracts. Antimicrobial peptides (AMPs) appeared to be a new approach both against microorganisms and for regulation of inflammatory and repair processes. To evaluate their potential usefulness in regenerative medicine, we prepared different extracts of neutrophil-derived AMPs from rabbit, ovine or porcine blood which contained AMPs of different compositions, mainly defensins, cathelicidins and fragments thereof. Then, we assessed in vitro the influence of different AMPs extracts on the neutrophils and monocyte-derived macrophages (MDM) activity. For this purpose, these cells were obtained from experimental animals, rabbits, or sheep submitted to insertion of a titanium implant into the tibial defect. The cultured cells stimulation was autologous or heterologous, dependently on the AMPs extract origin and the experimental animal species. The neutrophil activity was assessed on the basis of the enzymes release from azurophilic and secondary granules and the free radicals generation. The MDM functional assessment was based on the NO and superoxide generation and arginase activity. Additionally, morphological changes were evaluated in the cell cultures. Our results indicated that the origin of AMPs extract is crucial for its activity. The autologous extracts stimulated anti-inflammatory responses, whereas the heterologous extracts displayed pro-inflammatory effect on neutrophils and macrophages. These results might be considered during the introduction of new preparations in regenerative medicine.