A patient with ovarian cancer under long-term hemodialysis was treated with carboplatin at 240 mg/m2 via intravenous drip infusion for 30 min. Hemodialysis was performed 1 or 2 hrs after the administration of carboplatin. The pharmacokinetics of carboplatin were determined, plasma total and free carboplatin-derived platinum (total Pt and free Pt) levels declined rapidly in the former. The AUC, T1/2 and Cmax of total and free Pt were estimated to be 7.14 and 3.14 mg/ml x min, 35.1 and 18.2 h, and 15.1 and 10.0 micrograms/ml, respectively. Plasma total and free Pt levels showed the same as normal control in the latter. The AUC, T1/2 and Cmax of total and free Pt were estimated to be 8.70 and 5.09 mg/ml x min, 27.6 and 21.9 h, and 13.2 and 13.2 micrograms/ml, respectively. No severe side effect was observed after administration of carboplatin. In conclusion, carboplatin may be given to the patient 2 hrs before hemodialysis in view of the pharmacokinetics.