OBJECTIVE We evaluated the efficacy and tolerability of gemcitabine monotherapy in heavily pretreated, breast cancer patients as salvage chemotherapy. METHODS A weekly infusion of gemcitabine at 850 mg/m2 for 30 min, for 3 of every 4 weeks, was introduced in advanced breast cancer patients who had failed previous doxorubicin and taxane based chemotherapy. There was no dose modification, and the treatment was delayed until the leukopenia was recovered with G-CSF support. The efficacy was evaluated every three cycles and the treatment was continued until either disease progression or 12 cycles. RESULTS Of 41 enrolled patients, 38 were evaluable with a median age of 47. Total 178 cycles of gemcitabine was administered and the relative dose intensity was 89. The toxicity was mild with 12 of grade III neutropenia and 14 of grade III/IV thrombocytopenia without clinical symptoms. The response rate was 20 (8/38), comprising two complete and six partial responses. The median response duration and overall survival were 9 (2-25) and 11 months, respectively. The overall survival of 12 months was better in the third line patients than the 7 months in the fourth line treatment group. CONCLUSIONS Gemcitabine monotherapy is effective and safe as salvage treatment in heavily pretreated, breast cancer patients.