In a male cadaver dissected at the Department of Morphology, University del Valle, Cali (Colombia), a rarely described anatomical variation was found. It consisted of an aberrant termination or drainage of the thoracic lymph duct. Normally, this duct ascends in the thorax behind the esophagus, gradually diverges towards the left side of the neck and ends in the left jugulo-subclavian confluent--either in the internal jugular vein or in the subclavian vein. In the case of this cadaver, the thoracic duct diverged towards the right side of the neck to end in the right internal jugular vein. The present work describes the embryonic origin of the duct and offers a possible explanation for the anatomical variation encountered.