A 37-year-old male liver transplant recipient developed hemorrhagic shock from massive rectal bleeding a few hours after a protocol liver biopsy. Conservative treatment was not possible and the patient underwent a radiological investigation of the celiac and mesenteric arterial trunks, which showed active bleeding from a branch of the middle colic artery. Embolization with Tabotamp (Ethicon, Neuchatel, CH Switzerland) particles led to successful hemostasis. We thus discuss the possible mechanisms of injury. To our knowledge, no other cases of major rectal bleeding following percutaneous liver biopsy have been reported in the literature. We emphasize the need for Doppler ultrasound assistance, in terms of either preoperative examination with or without marking or guidance. The latter is the safest and most reliable technique, given the low risk of puncture of other organs and the low probability of obtaining an inadequate sample.