We evaluated the efficacy and toxicity profile of single-agent docetaxel administered in daily clinical practice at low-dose regimen in 37 pre-treated elderly patients with metastatic breast cancer previously exposed to chemotherapy. Docetaxel was employed by physician's preference according to a weekly (8 patients, 25-30 mg/m2 every 7 days), bi-weekly (19 patients, 40-50 mg/m2 every 14 days), or tri-weekly (10 patients, 75-100 mg/m2 every 21-28 days) schedule. The median age of patients was 70 yrs, and most of them (84%) had a good PS; visceral metastases were found in 26 patients. Twenty-five patients were pre-treated by two or more chemotherapy lines. Anthracycline or anthracycline/paclitaxel therapy was previously employed in 25 patients (67%). Median delivered dose-intensity of docetaxel was 21 mg/m2/week (range 11-32), without significant differences between the regimens used. Thirty-three patients were evaluable for response. Eight (24%) patients had objective responses (2 complete and 6 partial) to docetaxel, with a median duration of response of 18 months; 14 (42%) patients had stable disease lasting more than 6 months (median 10 months). Median overall time to progression was 6 months. Median overall survival was 16 months, with 1- and 2-year survival rates of 64% and 34%, respectively. Grade 3/4 toxicities were rare: leucopenia in 18% of patients, neutropenia in 13%, emesis in 8%, diarrhea in 5%, and mucositis in 5%. Severe fatigue was recorded in 4 patients. In conclusion, docetaxel, even when administered at low dose-intensity, demonstrated good disease control and toxicity profile. This approach provides an excellent alternative for pre-treated elderly patients with advanced breast cancer.