In a patient with advanced pancreatic cancer, with a hypercoagulable state, a complete clinical response was obtained with a mitomycin-based regimen plus adjunctive heparin. The patient converted from a partial response to a complete response with the addition of heparin, raising the possibility that heparin was somehow involved in the process. Recent studies have reported prolongation of survival in patients with cancer who were given heparin along with chemotherapy. The known antiangiogenic and antiproliferative action of heparin may explain this possible synergism. If heparin is, in fact, synergistic with cytotoxic cancer drugs, a fertile field of investigation is open to cooperative groups, especially because long-term heparin therapy is now feasible and safe, the low-molecular-weight heparins even more so.