Purpose: To evaluate the safety and efficacy of bevacizumab and weekly docetaxel as first- or second-line therapy in patients with metastatic breast cancer (MBC). Patients and Methods: Twenty-seven MBC patients received i.v. bevacizumab at 10 mg/kg on days 1 and 15 in combination with i.v. docetaxel 35 mg/m 2 on days 1, 8, and 15 of a 28-day cycle. Primary end points were to assess toxicity, overall response rate, and progression-free survival. A secondary end point was to assess the relationship between plasma endothelial and cell adhesion markers and clinical outcomes. Results: One-hundred fifty-eight treatment cycles were administered with a median of six cycles (range 1-15 cycles) per patient. The most common grade 4 toxicities per patient were as follows: 2 (7%)—pulmonary embolus, 1 (4%)—febrile neutropenia, and 1 (4%)—infection; grade 3 toxicities were 4 (15%)—neutropenia, 4 (15%)—fatigue, 2 (7%)—neuropathy, 2 (7%)—athralgias, 2 (7%)—stomatitis, 1 (7%)—pleural effusion, and 1 (4%)—hypertension. The overall response rate was 52% 95% confidence interval (95% CI), 32-71%, median response duration was 6.0 months (95% CI, 4.6-6.5 months), and the median progression-free survival was 7.5 months (95% CI, 6.2-8.3 months). In hypothesis-generating univariate and limited multivariate analyses, E-selectin was statistically significantly associated with response to the combination. Conclusion: Bevazicumab in combination with weekly docetaxel is active with acceptable toxicities in MBC. Additional studies evaluating E-selectin as a marker of response to bevacizumab-containing chemotherapy are warranted.