We performed CT lymphography on an 81-year-old female patient with a histologically confirmed squamous cell carcinoma of the tongue with no clinical or radiological evidence of cervical lymph node involvement. The lateral lingual lymph node was identified as a sentinel node, which is the first lymph node to receive drainage from a primary tumour. CT lymphography also showed draining lymphatics passing through the sublingual space, the medial side of the submandibular gland and near the hyoid bone and connected with the middle internal jugular node. Although metastasis to the lateral lingual lymph node is known as one of the crucial events in determining survival outcome in cancer of the tongue and floor of the mouth, very few reports are available on the imaging of the lateral lingual lymph node metastasis. This is the first report regarding the lateral lingual lymph node identified as a sentinel node demonstrated on CT lymphography. Dentomaxillofacial Radiology (2012) 41, 254-258. doi: 10.1259/dmfr/61883763