The respiratory burst of phagocytes plays an important role in the tissue damage that accompanies the inflammatory response. One of these conditions is allergic bronchial asthma, therefore, to evaluate the activation state of peripheral granulocytes the generation of reactive oxygen metabolites was evaluated using Luminol-enhanced chemiluminescence (LCL) and reduction of cytochrome C by superoxide. The resting granulocytes of the asthmatic patients under crisis showed a higher LCL compared to the noncrisis patients and control subjects. The granulocytes stimulated with PMA presented a significant increase in the respiratory burst in both groups of asthmatics. The granulocytes of noncrisis asthmatics challenged with Ops-Zym and with fMLP + Ops-Zym showed a higher metabolic activity, whereas the asthmatics under crisis presented no difference between reactive oxygen generation and that of the control group. The quantitative analysis of superoxide generation by granulocytes of the same patients did not show differences among the groups. Our findings suggest that the granulocytes of crisis and noncrisis asthmatics seem to be in a hyperreactive state and with a higher metabolic response when compared to the control group. However, the patients present a different behavior depending on stimulus used to activate cells. This could indicate that in peripheral blood exist different granulocyte populations depending on the inflammatory response taking place in the respiratory tract.