Eight patients with fever and neutropenia were given 2 g of ceftazidime i.v. as a bolus injection over the course of 3 min. The pharmacokinetic variables for ceftazidime were similar to those found previously in febrile, acutely ill, non-neutropenic patients. The area under the plasma-concentration-time curve was significantly smaller, and the terminal half-life (t1/2lambda(z)) significantly shorter, compared with elderly, healthy subjects (p < 0.005). Three patients survived long enough to be assayed after normalization of temperature and neutrophil counts. Glomerular filtration rates and clearances tended to be higher and the area under the curve and half-life lower on the day of fever and neutropenia. When considering our data in relation to known MIC values for common pathogens, ceftazidime administered intermittently every 6 h seems an appropriate regimen in patients with febrile neutropenia. Larger studies are needed to confirm this.