A sensitive, specific and highly reproducible method for the analysis of the two antineoplastics, ifosfamide and cyclophosphamide, in sewage water at the ppt-level is presented. The method includes a two-step solid-phase extraction (SPE) on C-18 and SiOH material and GC-MS analysis using single ion monitoring (SIM). The method was applied to degradational studies of the two drugs in laboratory-scale sewage treatment plants (LSSTPs) and to quantification in hospital sewage water samples. It was shown that the drugs were not degraded in LSSTPs and that they turned up in hospital sewage water