We studied the interactions between the neutrophilic granulocytes and three quinolone antibiotics, enoxacin, norfloxacin and pefloxacin, using the luminol-enhanced chemiluminescence method to evaluate the respiratory burst of the cells. Neutrophils obtained from healthy human volunteers were exposed to different therapeutic concentrations of the drugs for one and three hours and then opzonized zymosan was added to stimulate chemiluminescence reaction. None of the three drugs tested exercised any influence on neutrophil function.