Trastuzumab is a humanised monoclonal antibody that targets the extra cellular domain of human epidermal growth factor receptor-2 (HER-2), which is overexpressed in ~ 20% of human breast cancers. Clinical benefit has been shown in breast cancer patients with HER-2 amplification or overexpression when trastuzumab is used alone or in combination with chemotherapy. Docetaxel is one of the most potent chemotherapy agents in the treatment of patients with metastatic and early-stage breast cancer. The rationale for combining these two drugs is based not only on preclinical synergic data, but also on expanding clinical results. This article reviews the results of trials investigating this two-drug combination, as well as the triple combinations including docetaxel and trastuzumab with platinum salts. These combinations appear to be amongst the most active therapies for the treatment of patients with HER-2-positive breast cancer in metastatic and potentially adjuvant settings.