Disseminated intravascular coagulation (DIC) can be a rare initial manifestation of adenocarcinoma of the prostate. We present a case in which DIC was the symptom leading to the suspicion of a prostatic tumour. The performance of a prostate biopsy in this situation exacerbated the initial coagulation disorder. This case highlights the risks of prostate biopsy in patients with a suspicion of advanced adenocarcinoma of the prostate. The difficulty of treating DIC in this clinical situation is also discussed.