SUMMARY:The external jugular vein is increasingly being utilized as the recipient vein in head and neck free tissue transfers, and for cannulation in order to conduct diagnostic procedures or intravenous therapies. The variations in the patterns of its course, and knowledge of them, are therefore important. We report on a unique and previously non-described unilateral fenestration and duplication of the external jugular vein found during the neck dissection of a 77-year-old female cadaver. Embryological evaluation and clinical implications of the anomaly are described. Clinicians and surgeons performing neck vascular or reconstructive surgery should be aware of this variation of the external jugular vein in the hope of preventing inadvertent injury.