Twenty three patients with ovarian tumors were given intraperitoneal carboplatin (300 mg/m2) at different times before laparotomy and retroperitoneal lymphadenectomy. Total platinum (Pt) concentrations in the nodes, the peritoneum and other tissues were measured by flameless atomic absorption spectrometry. Histologic examinations were carried out for the nodes. In addition, Total platinum concentration of the plasma was determined in 3 cases. Peak Pt concentration in retroperitoneal nodes reached at 12 th hour after instillation, and the peak value was 13.38 +/- 1.85-21.57 +/- 7.80 micrograms/g, its AUC0-24th was 216.8 +/- 9.2-246.4 +/- 32.9 micrograms.h/g. AUC 0-24th for the fatty and connective tissues around th e pelvic nodes was 115.6 +/- 40.9 micrograms.h/g; it was significantly lower than AUC 0-24th for the nodes. AUC 0-24th for the pelvic peritoneum was 1 351.3 +/- 696.5 micrograms.h/g. Peak concentrations in the plasma were reached at the second hour after intraperitoneal carboplatin. Its peak value and AUC 0-24th were 6.7 +/- 1.0 microgram/L and 61.5 +/- 2.4 micrograms.h/L respectively. They were obviously lower than those for the nodes. These results indicate that after intraperitoneal carboplatin concentrations of the drug are higher in the retroperitoneal nodes than in the blood. Post chemotherapeutic histological cytodegeneration is found in the lymph nodes in some cases.