A substernal goitre is of clinical significance because its growth between the sternum anteriorly and vertebral bodies posteriorly leads to impingement on the surrounding structures and compressive symptoms. The incidence of substernal goitre is documented to vary between .02 and .5%. It accounts for 3-12% of mediastinal masses and is the most common superior mediastinal mass. This condition is important because it presents a diagnostic dilemma as its size and compressive symptoms mimic malignant disease, and an operative dilemma for the approach to its management. We present one of the largest reported retrosternal goitre cases in the literature.