Epileptic seizures are a frequent manifestation of Hashimoto's encephalopathy. However, status epilepticus associated with Hashimoto's encephalopathy are not well characterized in medical literature. We described here a 16-year-old girl who presented with complex partial status epilepticus associated with elevated anti-thyroid antibodies. Ictal EEG showed lateralized high amplitude rhythmic delta waves over the right hemisphere and ictal single-photon emission computed tomography revealed regional hyperperfusion of the right parietal and temporal lobes. The patient was unresponsive to antiepileptic drug therapy but responded to intravenous steroid treatment. Screening of serum anti-thyroid antibodies for unexplained encephalopathy with epileptic seizures is suggested, as early recognition and prompt steroid treatment may lead to a favorable prognosis.