The interaction of leukocyte inhibitory factor (LIF), a lymphokine that acts as a cell-directed inhibitor of neutrophil locomotion, with the plasma membrane of its target cell was studied. LIF bound specifically to intact neutrophils and to neutrophil plasma membrane vesicles but not to intact macrophages, erythrocytes, or plasma membrane vesicles obtained from these cells. Although LIF adhered tightly to the neutrophil plasma membrane and was not removed by extensive washing, LIF activity could be eluted with N-acetyl-D-glucosamine. Elution with galactose, fucose, and N-acetyl-D-galactosamine did not remove LIF from the neutrophil plasma membrane. Similarly, N-acetyl-D-glucosamine, but not galactose, interfered with the binding of LIF to neutrophil plasma membrane vesicles. It is proposed that LIF binds to a high-affinity neutrophil plasma membrane site and that some intrinsic neutrophil locomotory abnormalities may represent tightly bound inhibitors of migration.