The purpose of this study was to evaluate the toxicity and efficacy of paclitaxel/gemcitabine administered every 2 weeks in the first-line treatment of advanced breast cancer. Forty-three chemonaive patients with histologically confirmed metastatic breast carcinoma were enrolled. Patients received paclitaxel 150 mg/m2 followed by gemcitabine 2,500 mg/m2, both on day I of a 14-day cycle, for a maximum of eight cycles. Thirty-four patients were evaluable for toxicity; 38 were evaluable for efficacy. The median age at the time of diagnosis was 54 years, the median performance status was 90, and the median number of lesions was three. Most patients (71%) had received prior adjuvant therapy. Grade 3 and 4 toxicity was limited to leukocytes (14% and 18%, respectively). Grade 3 toxicities (5% each) were thrombocytopenia, nausea and vomiting, elevation of aspartate transaminase, neurosensory, and constipation. One patient had neutropenia and fever. The objective response rate was 68% (21% complete response and 47% partial response); 18% had stable disease and 13% had partial disease. The preliminary evaluation of paclitaxel/gemcitabine given as a 2-week schedule to patients with untreated advanced breast carcinoma shows encouraging activity and a favorable toxicity profile.