The prognostic value of various demographic, clinical and laboratory characteristics was investigated in 54 patients with metastatic breast cancer during first-line paclitaxel chemotherapy. As a single-agent treatment, paclitaxel (175 mg/m2) was given by 3-hour infusion every three weeks. The overall response rate was 30%. The follow-up ranged from 3 to 65 months (median 17 months). The most important pretreatment prognostic factors for survival were found to be hemoglobin (Relative Risk-2.26; p = 0.02) and serum lactic dehydrogenase (RR-1.81; p = 0.04) levels. The survival showed a strong association to the type of response. The median survival for responders was 5-fold greater than for patients with progressive disease (30.2 months and 5.7 months, respectively). Following the first-line paclitaxel treatment the estimates of tumor response became the major predictor of survival (RR-12.3; p < 0.0001).