In cases of treatment-resistant schizophrenia the combined application of antipsychotic drugs often becomes necessary. Clozapine has been combined successfully with other atypical antipsychotic drugs such as risperidone or amisulpride in the past. We report the difficult treatment of a 28-year-old schizophrenic woman. Psychotic symptoms were found resistant to monotherapy with clozapine or ziprasidone. In contrast, combined application led to a marked improvement in both positive and negative symptoms of schizophrenia along with a decrease of side effects.The reported combination is a promising option in cases of treatment-resistant schizophrenia and should be further evaluated in prospective studies.