The pharmacokinetics of teicoplanin infused for 30 min at a dose of 6 mg kg-1 was studied in 11 infected patients under continuous arterio-venous haemofiltration (CAVH). Serum teicoplanin levels were assayed by h.p.l.c. over 24 h. After 0.5 h, i.e. at the end of the infusion, the mean plasma concentration was 49.6 +/- 15.1 mg l-1. At the last sampling time (24 h), the mean concentration was 2.6 +/- 1.0 mg l-1. The concentration of teicoplanin was determined in the haemofiltrates. The percentage of the administered dose recovered in the haemofiltrate was low: less than 1% for seven patients, between 1.8 and 3.7% for three patients and 7% for one patient. CAVH patients should be given teicoplanin using the same dosage regimens as previously described for patients with renal impairment.