Common complications related to transrectal ultrasound (TRUS) guided prostatic needle biopsy are hematuria, hematospermia, and hematochezia. To the best of our knowledge, we report the second case of a very large hematoma extending from the pelvis into the retroperitoneal space in literature.A 66-year-old man with a serum prostate-specific antigen (PSA) of 5.4 ng/ml was admitted to our department for a TRUS-guided prostatic needle biopsy. Laboratory values on the day before biopsy, including coagulation studies, were all normal. The patients did not take any anticoagulant drugs. No immediate complications were encountered. Nevertheless, 7 hours after the biopsy, the patient reached our emergency department with severe diffuse abdominal pain, hypotension, tachycardia, and confusional state. He underwent an ultrasonography and then a computed tomography (CT) scan that showed "a blood collection in the pelvis that extending to the lower pole of left kidney associated with a focus of active contrast extravasation, indicating active ongoing prostate bleeding." Consequently, he underwent a diagnostic angiography that showed no more contrast extravasation, without the need of embolization. Management of hematoma has been conservative and hematoma was completely reabsorbed 4 months later.