Aim and background: Hyperthyroidism is frequently associated with irritability, anxiety, restlessness, impairment in concentration, insomnia, and fatigue. Rarely such patients can also develop mania, depression, and even delirium. Psychosis is a rare complication of hyperthyroidism and has been reported in 1% of cases. A thyroid storm is a life-threatening endocrine emergency with an incidence rate of 1 to 2%. Hence, knowing the common and uncommon presentations of thyroid storm is important for its prompt diagnosis and treatment. In this article, we present an unusual case where psychosis was the manifesting symptom of thyroid storm. Case description: A 55-year-old woman presented to the psychiatry outpatient department with features of psychosis, agitation, and suicidality. Upon admission, the patient was started on antipsychotics but showed no improvement in restlessness and autonomic hyperactivity. Investigations in the upcoming days revealed hyperthyroid status, and a diagnosis of thyroid storm was considered. She was treated with methimazole and propranolol, which improved. Despite improvement in other domains, she continued having hallucinations and delusional ideas, for which antipsychotic treatment was continued. She achieved remission within six months and was reportedly euthyroid on regular medications. Conclusion: Recognition of organic causes of psychiatric presentations is crucial for successful treatment outcomes. Clinical significance: Psychosis can at times be the only presentation of a severely deranged thyroid profile. Hyperthyroidism leading to thyroid storm is an emergency and treatment of such patients should be multidisciplinary in approach. It poses a therapeutic challenge as delay or lack of appropriate medical treatment can result in significant morbidity and even mortality.