The present work focuses on the fate of two cancerostatic platinum compounds (CPC), cisplatin and carboplatin, as well as of two inorganic platinum compounds, [PtCl(4)](2-) and [PtCl(6)](2-) in biological wastewater treatment. Laboratory experiments modelling adsorption of these compounds onto activated sludge showed promising specific adsorption coefficients K(D) and K(OC) and Freundlich adsorption isotherms. However, the adsorption properties of the investigated substances were differing significantly. Adsorption decreased following the order cisplatin>[PtCl(6)](2-)>[PtCl(4)](2-)>carboplatin. LogK(D)-values were ranging from 2.5 to 4.3 , logK(OC) from 3.0 to 4.7. A pilot membrane bioreactor system (MBR) was installed in a hospital in Vienna and fed with wastewater from the oncologic in-patient treatment ward to investigate CPC-adsorption in a sewage treatment plant. During three monitoring periods Pt-concentrations were measured in the influent (3-250 microg l(-1) Pt) and the effluent (2-150 microgl(-1) Pt) of the treatment plant using ICP-MS. The monitoring periods (duration 30d) revealed elimination efficiencies between 51% and 63% based on averaged weekly input-output budgets. The derived logK(D)-values and logK(OC)-values ranged from 2.4 to 4.8 and from 2.8 to 5.3, respectively. Species analysis using HPLC-ICP-MS proofed that mainly carboplatin was present as intact drug in the influent and--due to low logK(D)--in the effluent of the MBR.