<p>This study aimed to contribute to scientific and technological advancements in surgical techniques by evaluating the anatomical course of the accessory nerve in the neck region through cadaver dissections. Bilateral neck dissections were performed on eight adult male cadavers fixed in formalin at the Anatomy Department of Dokuz Eylul University Faculty of Medicine. All measurements were taken based on marked reference points and horizontal planes. The accessory nerve crosses the internal jugular vein anteriorly at the lower edge of the posterior belly of the digastric muscle in 10 neck sides (62.5%). In two neck sides, we observed that a branch of the accessory nerve was separated through the sternocleidomastoid muscle before passing behind it (12.5%). The length of this nerve in the posterior neck region was 52.3 ± 9.88&#xa0;mm, and was significantly greater on the left side (<i>p</i> = 0.036). The accessory nerve was tortuous unilaterally in two cadavers. In some cases, a branch of the accessory nerve was found proximally to the anterior border of the trapezius muscle, and a superficial lateral cervical lymph node was located very close to the accessory nerve. The study revealed significant individual variations in the course of the accessory nerve. To reduce the risk of accessory nerve damage and shoulder syndrome during surgical procedures, it is crucial to comprehend the position, course and distances of anatomical structures associated with the posterior belly of the digastric muscle, the sternocleidomastoid muscle and the trapezius muscle.</p>