Numerous pathologies diagnosed in the emergency department (ED) are treated with invasive procedures involving anesthetic and surgical risks. Retropharyngeal abscess is a serious condition requiring emergent treatment, often in need of trans-oral incision and drainage under general anesthesia. A misdiagnosis, especially after surgical treatment, might generate undesirable consequences, more so if the final diagnosis is a non-surgical pathology such as longus colli (LC) tendonitis. To discuss the etiology, differential diagnosis and treatment of LC tendonitis, a clinical condition still misdiagnosed despite advanced imaging techniques. A middle-aged man presented to a satellite ED with sore throat, neck pain and stiffness. A computed tomography (CT) scan of the neck with intravenous contrast was read as retropharyngeal abscess. He was transferred to our ED after acceptance by ear-nose-throat (ENT) surgery. He was scheduled for open incision and drainage under general anesthesia. A detailed evaluation by our ED staff revealed a nontoxic patient with no compromise of the airway. His physical exam was unrevealing and a second review of the CT demonstrated typical radiological signs for LC tendonitis. After a discussion with ENT the patient was discharged home on anti-inflammatory medications and oral steroids. He recovered well and no further intervention was needed. Longus colli tendonitis is a rare condition that mimics emergent surgical conditions. Emergency physicians are qualified to make a clinical and radiological diagnosis. While CT scan can provide a diagnosis, the primary evaluation tool is an adequate medical interview and physical exam.