Background: Radioiodine (RAI) therapy for Graves’ disease is a well-accepted and effective treatment with a good side effect profile. Short-term adverse effects can occasionally include radiation-induced thyroiditis. To my knowledge, cervical lymphadenitis associated with RAI therapy for Graves’ disease has not been reported before. Case Report: A 38-year-old woman initially presented with uncontrolled thyrotoxicosis secondary to Graves’ disease. She subsequently received RAI therapy for her condition. Within a week, she developed painful bilateral cervical lymphadenopathy that progressed to abscess formation requiring incision and drainage. No other causes (neoplastic or infective) were found. Symptomatic treatment was instituted, and within 2 months the lymphadenitis resolved completely. Discussion: RAI therapy for Graves’ disease can sometimes cause radiation-induced thyroiditis but associated cervical lymphadenopathy or lymphadenitis has not been described. This may represent a continuum of the proinflammatory state induced by RAI manifesting as a rare but potentially morbid complication.