We have studied the penetration of cefuroxime and ceftazidime into lung tissue of 40 patients subjected to pulmonary surgery. Samples of blood and lung tissue were taken 1 and 2 h after antibiotic administration. Patients were randomly assigned to four dosage schedule groups: group A received a single intravenous injection of 750 mg cefuroxime; the lung tissue levels at 1 and 2 h were 9.6 +/- 3.1 and 4.54 +/- 2.64 micrograms/g of cefuroxime; the percentage penetration from serum into the lung tissue was 33.7 and 34.6%, respectively. Group B patients received three doses of 750 mg cefuroxime; lung tissue levels were 17.1 +/- 7.7 and 14.7 +/- 5.4 micrograms/g, the percentage of penetration being 89.1 and 102.8% at 1 and 2 h. Group C received a single intravenous injection of 1 g ceftazidime; the lung tissue levels were 16.3 +/- 10.1 and 10 +/- 5.04 micrograms/g; the percentage of penetration from serum was 38.3 and 35.3%. Group D received three doses of 1 g ceftazidime; the lung tissue concentrations were 11.98 +/- 7.5 and 8.5 +/- 7.3 micrograms/g and the percentage of penetration 35.1 and 32.2% at 1 and 2 h after last dose.