The anthracyclines are among the most active agents in the treatment of breast cancer. In recent years, the taxoids have produced promising results as single agents in breast cancer. Average overall response rates of 43% in previously untreated and 29% in pretreated metastatic breast cancer have been reported in phase II trials with paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ). Based on the known activity of doxorubicin and the single-agent phase II results of paclitaxel, two phase III randomized trials comparing these drugs as monotherapy in first-line, with crossover on progression, were conducted by the European Organization for Research and Treatment of Cancer and the Intergroup. The preliminary results of these studies were presented at international congresses and will be discussed here.