Fluoroquinolones have been studied extensively as prophylaxis in neutropenic cancer patients. There is a large body of evidence suggesting that fluoroquinolones are a valuable choice for preventing bacterial infections in neutropenic cancer patient. As yet, there is no question that prophylaxis with fluoroquinolones has led to a decrease in the occurrence of gram-negative infections in neutropenic patients. By contrast, the benefits of fluoroquinolone prophylaxis on other parameters of infection-related morbidity and on the occurrence of infection-related mortality are not clear. Moreover, the use of fluoroquinolones is not without risk. Reports of fluoroquinolone-resistant Escherichia coli causing bacteremia among cancer patients are matter of concern. Recent well conducted, large clinical trials confirm the long lasting interest in the use of fluoroquinolones prophylaxis. Moreover, a reduction in mortality has been demonstrated in recent metaanalyses, though the generalizability of this finding is uncertain. Reports from cancer centers in Europe have shown a rebound of gram-negative bacteremias after discontinuation in the use of prophylaxis with fluoroquinolones. In light of the these findings, prophylaxis with a quinolone during granulocytopenia, where resistance permits, is still appropriate.