Surgical therapy for early lesions of the tongue should have the potential to be both oncologically sound and easy to rehabilitate. Obviously, the amount of tongue left behind after surgery is proportional to the post-operative function. Hence accurate mapping of the diseased tongue is of paramount importance in order to limit or extend the resection margins. We have evaluated the use of ultrasound in carcinoma of the tongue, and also compared its relative accuracy with physical examination for determining the extent of growth, keeping the histopathological size as a gold standard. We found that ultrasound is more accurate in detecting T2 and T3 tumours than T1 lesions. Intraoral sonographic mapping may be the answer for such small lesions. In addition, ultrasonography is beneficial in showing spread to contiguous areas of the tongue. However, post-radiation fibrosis and frank residual disease were not differentiated accurately by ultrasound. Thus ultrasonography can be an effective investigative tool and together with physical examination it can increase diagnostic accuracy leading to precise surgery for carcinoma of the tongue.