A phase II trial was performed to investigate the efficacy and tolerance of combined gemcitabine and liposomal doxorubicin +/- recombinant human granulocyte colony-stimulating factor (G-CSF) in patients with chemotherapeutically pretreated metastatic breast cancer. Thirty-four patients were entered in this trial. Chemotherapy consisted of gemcitabine and liposomal doxorubicin +/- G-CSF. Twenty seven patients received this regimen as 2nd line therapy, five patients as 3rd line and two patients as 4th line therapy after having failed taxane- and/or anthracycline-based chemotherapy or other drug combinations. After a median of six courses, an overall response rate of 26% (9 PR in 34 enrolled patients) was observed; 14 patients had disease stabilization (41%), and eight (24%) progressed. Three patients were not evaluable for response due to anaphylaxis after the first course and protracted thrombocytopenia. The median TTP was 7.5 months, and median overall survival was 15 months. Myelosuppression was the most frequently observed toxicity. Non-haematological side effects were generally mild to moderate. Our data suggest that gemcitabine and liposomal doxorubicin +/- G-CSF is an effective and fairly well tolerated regimen for chemotherapeutically pretreated patients with advanced breast cancer.