The most common use of radioembolization is in the treatment of primary and secondary liver tumors, and the most common radioisotope used is yttrium-90. This form of therapy has been proven to be successful in achieving tumor reduction and prolonging survival. Adverse events, although uncommon and usually self-limiting, have been reported. The present report describes a case of radiation dermatitis caused by shunting of 90Y microspheres to the anterior abdominal wall via a patent falciform artery. When identified, prophylactic embolization of this patent artery may prevent the potential adverse event of radiation-induced dermatitis after radioembolization.