The alkaloid ecteinascidin-743, isolated from the marine tunicate Ecteinascidia turbinata, binds to DNA and induces cytotoxic effects in several tumors. The drug is being codeveloped by Pharma Mar and Ortho Biotech. In May 2001 and October 2003, it was granted orphan drug status by the European Commission for soft tissue sarcoma and ovarian cancer, respectively. This paper reviews its research progress, including chemical synthesis, in vitro studies and mechanism of action, antitumor activity in vivo, toxicity, pharmacokinetics, and clinical studies.