We present a case involving a 60-year-old male with multifocal hepatocellular carcinoma (HCC), emphasizing the critical need for vigilant post-procedural monitoring following the interruption of drug-eluting beads transarterial chemoembolization (DEB-TACE) due to an allergic reaction. The patient, who had a history of various treatments for HCC, underwent DEB-TACE. During the procedure, he experienced an anaphylactic shock, presumably due to an allergy to the treatment components (iodinated contrast agent), resulting in the procedure's discontinuation. Initially stable, the patient was later found to have intra-abdominal bleeding, a complication associated with the vascular lake phenomenon (VLP), detected on post-procedural imaging. Re-embolization using gelatin particles was performed to address the VLP. It remains unclear whether the shock experienced during the DEB-TACE procedure was due to the allergic reaction or the rupture of the VLP. This case underscores the complexities in managing DEB-TACE, the necessity of careful monitoring for VLP, and the challenges in diagnosing and managing allergic reactions during such procedures. In conclusion, it is crucial to consider that VLP can occur at any time during or after DEB-TACE. Assessing the presence of VLP using digital subtraction angiography before the termination of the procedure is essential. However, when an allergy to the iodinated contrast agent is suspected, as in this case, careful follow-up with abdominal ultrasound and computed tomography might be necessary to assess the presence of intra-abdominal hemorrhage associated with VLP.