Thyroid Hemiagenesis is a rare entity with only about a hundred cases reported worldwide so far. It is usually the left lobe that is absent in 80% of the cases. The thyroid lobe that is present is usually enlarged and could be afflicted with one of the most common thyroid disorders (hyperthyroidism and hypothyroidism). Ultrasound, thyroid scan are useful investigations in diagnosis of this rare entity. Treatment options are usually based on the clinical profile of the patient.