Strong evidence suggests that neutrophils may play an active role in acute and chronic inflammatory disorders, such as rheumatoid arthritis and atherosclerosis. Given the role of pro-inflammatory cytokine TNF-α in these inflammatory processes, we planned the present study to investigate the effect of short term incubation with TNF-α on neutrophil migration to CCL3, a chemokine produced in inflammatory sites and normally devoid of neutrophil chemotactic properties. We found that TNF-α primed neutrophils for migration to CCL3 via CCR5. TNF-α-induced migration was a consequence of the TNF-α-induced up-regulation of integrin CD11b/CD18 (Mac-1) on neutrophil surface. Furthermore, TNF-α activity was found to be strictly dependent on the activation of ERK 1/2 p44, cooperating with the intracellular pathways involving Src kinases, PI3K/Akt, p38 MAPK, well known as activated in response to classical chemoattractants (CXCL8) or priming agents (GM-CSF). On the contrary, the effect of TNF-α on neutrophil migration to CCL3 was not dependent on JNK 1/2. In conclusion, the present report shows that TNF-α unveils a previously unknown capacity of neutrophils to migrate to CCL3 through the intervention of Mac-1. TNF-α regulates Mac-1 up-regulation through signalling pathways, involving various kinases, but not JNK 1/2. Although highly speculative, ERK 1/2 p44 may represent a selective target for the pharmacologic manipulation of neutrophil-mediated adverse activities in TNF-α-mediated inflammatory states.