This case report explores a rare presentation of restless legs syndrome (RLS) in a 59-year-old female with a history of Graves' disease (GD), highlighting the diagnostic challenges and the importance of considering thyroid dysfunctions in RLS. The patient, previously diagnosed and treated for GD, presented with acute nocturnal discomfort in her lower limbs, along with symptoms of fatigue, weight loss, and palpitations. Physical examinations and thyroid function tests indicated a recurrence of GD. Her RLS symptoms notably resolved following the treatment of GD with methimazole, pointing towards secondary RLS induced by GD. This case emphasizes the necessity of a comprehensive diagnostic approach in RLS, particularly in differentiating it from mimicking conditions including leg cramps, arthritis, peripheral neuropathy, and drug-induced akathisia, and identifying underlying etiologies like thyroid dysfunctions. The resolution of RLS symptoms after GD treatment underlines the potential link between thyroid dysfunctions, iron metabolism, and the dopaminergic system in RLS pathophysiology.