Neutrophil phagocytic function was studied in fifteen patients with chronic fasciolosis and five in the incubating phase of the disease. Results were compared with a control group. The chematactic index which is the ratio of directed to non directed migration, the (NBT) reduction test which estimates phagocytosis and the more recent and specific test the chemiluminescence which measures phagocytosis and intracellular killing were performed. The results showed that in fasciolosis chemotactic activity, NBT and chemiluminescence index were significantly increased as compared to controls. This increase was more prominent in the acute phase. In this stage, the immature parasites are in close contact with the liver tissue. With chronicity of infection, they reach the bile ducts and inflammation in the liver parenchyma subsides. At this stage a lower level of metabolites and antigens reach the tissues, while the majority pass with bile to the intestinal lumen. The indices returned to normal level after treatment of fasciolosis. This signifies disappearance of all stimuli responsible for activation of PMN phagocytes.