Primary non-Hodgkin’s lymphoma of the thyroid gland was rarely described. We report the case of a 44-year-old man admitted for an anterior neck swelling, hoarseness and dyspnea. The chest radiograph showed a trachea deviation. He had no clinical, biological or radiological sign of other lymphoma locations. Ultrasound examination of the neck revealed a bilateral heterogeneous thyroid lesion. Cytology revealed lymphoid cells having high nuclear-cytoplasmic ratio with multiple and irregular nucleoli. An urgent thyroid surgery consisting of total thyroidectomy had been performed since the presence of compressive signs due to the tumor. The histopathological examination of a biopsy from the thyroid tissue confirmed a high-grade non-Hodgkin’s lymphoma. Then, L-thyroxin substitution therapy, chemotherapy and radiotherapy were initiated. A prolonged remission was noted.