The ability of regenerate whole-body structures has been long studied in both vertebrate and invertebrate animal models. Regeneration of arms in Cephalopods and in particular in Octopods has been the subject of several studies. Octopods often lose arms or part of them throughout life and they are endowed with a high regenerative power. Due to this extraordinary regeneration capability here we propose the use of the Cephalopod Octopus vulgaris as a model of regeneration. This study represents the first attempt to exploit regeneration markers to identify the pattern and distribution of proliferating cell type during the octopus arm morphogenesis. In order to follow cell replacement in various arm regions, we first assessed the expression of specific markers involved in cellular proliferation (AgNOR and PCNA). Several studies have pointed toward the role of acetylcholine esterase (AChE) in the regeneration process in both vertebrate and invertebrate. Due to the typical cholinergic innervation of the octopus arm we investigated the possible role of the AChE in arm regeneration. We tested the hypothesis that AChE activity plays a major role in the regenerative process. Our data show that the activity and localization of this enzyme vary during regeneration and are related to the proliferation stage of the regenerative process. This suggests AChE may have an important influence in the regeneration process and it could then be considered as a potential target to promote or regulate the regenerative process.