The diverse physiological functions of histamine are mediated through distinct histamine receptors. Mast cells are major producers of histamine, yet effects of histamine on mast cells are currently unclear. The present study shows that histamine induces chemotaxis of mouse mast cells, without affecting mast cell degranulation. Mast cell chemotaxis toward histamine could be blocked by the dual H₃/H₄ receptor antagonist thioperamide, but not by H₁ or H₂ receptor antagonists. This chemotactic response is mediated by the H₄ receptor, because chemotaxis toward histamine was absent in mast cells derived from H₄ receptor-deficient mice but was detected in H₃ receptor-deficient mast cells. In addition, Northern blot analysis showed the expression of H₄ but not H₃ receptors on mast cells. Activation of H₄ receptors by histamine resulted in calcium mobilization from intracellular calcium stores. Both Gαi/o proteins and phospholipase C (PLC) are involved in histamine-induced calcium mobilization and chemotaxis in mast cells, because these responses were completely inhibited by pertussis toxin and PLC inhibitor 1-[6-[[17β-3-methoxyestra-1,3,5 (10)-trien-17-yl]amino]hexyl]-1H-pyrrole-2,5-dione (U73122). In summary, histamine was shown to mediate signaling and chemotaxis of mast cells via the H₄ receptor. This mechanism might be responsible for mast cell accumulation in allergic tissues.