Disseminated intravascular coagulation (DIC) associated with prostate adenocarcinoma is a bad prognostic sign. Most of the cases are limited to biological abnormalities. Some, however, come to medical attention due to thromboembolic or hemorrhagic complications. We report 4 such cases and review the pertinent literature. The characteristic features are low platelets and coagulation factors in an elderly man. In two out of the four cases, bleeding due to the DIC revealed the cancer. All patients received hormonotherapy and heparin. The worst fate (case 3) was a subacute one with no effect of the drugs and death in a short time. The other cases went into a five- to seven months remission before uncontrollable bleeding led to death. No favorable effect of the chemotherapy was observed. Thus, new treatments are sought for this rare but ominous complication of prostate cancer.