Twenty-two days after administration by intravenous bolus, of 50 mg of adriamycin to several patients we found concentrations of adriamycin and adriamycinol of the order of 100 pcg/ml. In theory, however, with a terminal half-life of 30 h, the plasma levels of adriamycin and adriamycinol should be close to 0.1 pcg/ml. Further pharmacokinetic investigation was therefore necessary. We have retained for this study nine male patients, aged between 53 and 69 years who received 25 to 50 mg of adriamycin by slow intravenous injection. The HPLC method permitted the detection of 50 pcg/ml of adriamycin and adriamycinol, with the possibility of monitoring their elimination during 120 h (and in one case during 160 h). The terminal half-lives of elimination estimated in 8 patients were respectively 110 +/- 52 h for adriamycin and 92 h 50 min +/- 43 h for adriamycinol. Surface ratios under adriamycinol curves against calculated adriamycin was 1.10 +/- 0.26. Plasma levels found during the To in certain patients correspond to the end of the drug elimination of the previous treatment. It is difficult with a half-life to 110 h to predict the effects of residual concentrations of adriamycin and adriamycinol.