The cytostatic drug ifosfamide (IFF) and its main metabolites 2-dechloroethyl ifosfamide (2-D-IFF) and 3-dechloroethyl ifosfamide (3-D-IFF) were isolated from the plasma matrix with high recovery by solid phase extraction using Bakerbond C18-cartridges. A further cleaning of the extracts is not necessary. An effective separation of IFF and metabolites from interfering compounds present in urine samples prior gc was performed with Extrelut-1 and dichloromethane/isopropanol (95:5, v/v). The described assays may be used for pharmacokinetic studies as well as drug monitoring in the clinical laboratory.