SARS-CoV-2 infection was declared a pandemic in 2020 and affected millions of people worldwide. Angiotensin-converting enzyme-2 receptors, through which coronavirus enters the cells of different organs, have been detected in the thyroid gland. The most common cause of thyrotoxicosis is Graves' disease in which thyroid-receptors antibodies (TRAb) stimulate the TSH receptor, increasing thyroid hormone production and release.A 22-year-old woman had symptoms of palpitation, tremor, muscle weakness, anxiety and sleep disturbance. 3 weeks before the onset of these symptoms, the patient suffered from COVID-19, which lasted 14 days and was characterized by a course of moderate severity with fever up to 38°C, general weakness without shortness of breath. The patient had no pre-existing thyroid problems. Her TSH was <0.01 mU/L, FT4, FT3 and TRAb were increased. Antithyroid drugs, glucocorticosteroids and β-blockers were prescribed. During 3 months of treatment doses of methimazole, methylprednisolone and bisoprolol were gradually reduced due to the improvement of the patient's condition and thyroid tests normalization.COVID-19 infection can cause Graves' disease and thyrotoxicosis. The onset of this disease after SARS-CoV-2 does not depend on the presence of pre-existing thyroid pathology and requires the appointment of glucocortisteroids.