Acute polyneuropathy is a rare manifestation of severe hyperthyroidism. We report a 22-year-old Omani male who presented to the Sohar Hospital, Sohar, Oman, in 2016 with acute-onset rapidly progressive flaccid areflexic paraplegia as the presenting manifestation of thyrotoxicosis. Nerve conduction studies revealed mixed axonal and demyelinating polyneuropathy in both the motor and sensory nerves. Treatment of the hyperthyroidism with β-blockers and carbimazole along with physiotherapy resulted in the patient's full recovery and the alleviation of his symptoms. Besides highlighting this rare association, this report underscores the importance of including thyroid function tests in the evaluation of patients with acute polyneuropathy