Low-energy laser (He-Ne) irradiation (LELI) was found to promote skeletal muscle regeneration in vivo. LELI has a direct effect on myogenic cells, since the same response (delayed differentiation and enhanced proliferation) was obtained in vitro upon treatment of primary rat satellite cells, of an established line of mouse satellite cells, and of satellite cells derived from single fibres cultures. The Laser effect is similar to that elicited by a true mitogenic stimulus: it is in fact mediated by activation of growth factor receptors and of the mitogen-activated protein kinase cascade, and not by the so called stress-activated protein kinases. However, in contrast to the potential oncogenicity of a mitogen, LELI is completely safe from this point of view. This technique could be potentially applied to boost muscle regeneration after an injury or surgery, or to improve myoblast transplant. -He-Ne laser irradiation (LELI) is a completely safe non-invasive procedure which was found to promote skeletal muscle regeneration in vivo. - The specific field of science or technology where LELI could find an application are Medicine (A26) or Surgery (A37), in particular, myoblasts transplant. -Currently myoblasts are considered the preferred cell type to serve as vectors for the introduction of foreign genes into patients (gene therapy) since they are easily accessible, can be grown and genetically manipulated in vitro, and, upon re-implantation, they differentiate into myotubes which are among the most long-lived cells in our bodies. -Our results show that LELI could enhance myoblasts proliferation in vitro during the expansion step or in vivo after re-implantation.