Neuropeptides play an important role in the active communication between the nervous and immune systems. Substance P (SP) is a major neuropeptide involved in inflammation and has been reported to exert various proinflammatory actions on inflammatory leukocytes including neutrophils. The current study further investigated the modulatory effect of SP (1µM) on chemokine production and chemokine receptor expression in primary mouse neutrophils. Our results showed that SP primed neutrophils for chemotactic responses to not only the CXC chemokine macrophage inflammatory protein (MIP)-2 but also the CC chemokine MIP-1. The activating effect of SP on neutrophils was further evidenced by an upregulation of CD11b integrin, the activation marker of neutrophils. SP induced both the mRNA and protein expression of the chemokines MIP-1 and MIP-2 in neutrophils and upregulated the chemokine receptors CC chemokine receptor (CCR)1 and CXC chemokine receptor (CXCR)2. This stimulatory effect of SP on chemokine and chemokine receptor expression in neutrophils was further found to be neurokinin-1 receptor (NK-1R)-mediated. Pretreatment with a potent, selective NK-1R antagonist CP96,345 inhibited SP-induced activation of neutrophils and upregulation of chemokine and chemokine receptor expression. Moreover, SP-induced chemokine upregulation was NFB-dependent. SP time-dependently induced NFB p65 binding activity, IB degradation and NFB p65 nuclear translocation in neutrophils. Inhibition of NF activation abolished SP-induced NF binding activity and upregulation of MIP-1 and MIP-2 in neutrophils. Taken together, these results suggest that SP exerts a direct stimulatory effect on the expression of both chemokines and chemokine receptors in primary mouse neutrophils. The effect is NK-1R-mediated involving NFB activation.