While in clinical research epidemiological data indicate a higher prevalence of chronic pain in women, preclinical research has long focused on male animal models. Recently, in the study of neuropathic pain, it was found that mechanisms responsible for pain behavior after a peripheral nerve injury in male differed from the ones in female. At a time when gender equality is being claimed, science is reviewing its copy and has to find the sex differences that could lead to new and appropriate therapeutic targets.