We review experimental and clinical data on the pharmacokinetics and pharmacodynamics of antibacterial drugs in febrile neutropenic hosts. Since major pharmacokinetic changes have been reported for various classes of antibiotics in these patients, we advocate the need for adequate initial dosing regimens in all cases. Monitoring drug serum concentrations is mandatory for aminoglycosides and glycopeptides, and special attention should be paid to the dosing frequency of the short half-life beta-lactams to optimise the management of febrile neutropenia, especially in patients with severe sepsis.