Abstract Rationale: Knowledge of the venous systems of the neck is important in microvascular anastomosis as well as to avoid unintended bleeding during neck dissection. Patient Concerns: We present three rare variations of the jugular system of the neck which could have complicated neck dissection. Diagnosis: The first case is of a posterior tributary from an internal jugular vein (IJV). The second case is an IJV with increased diameter of 3 cm and the third case is an aneurysm of the external jugular vein. Treatment: Careful dissection was carried out to avoid complications and to preserve the vessels for microvascular anastomosis. Outcome: No complications were encountered intraoperatively and post-operatively. Take-away Lessons: Variations from normal anatomy should be dealt with caution to avoid complications and to perform surgery precisely and efficiently.