A 50-year-old male presented with a one-day history of right leg weakness, numbness, and urinary retention. Weakness was present for two weeks but worsened significantly during the last 24 hours. On the right there was sensory loss in the leg and below the Th8 dermatome. On the left there was sensory loss below the Th10 dermatome and distal loss of temperature sensation. Past medical history revealed a cervical trauma 30 years ago when a glass chip lodged into the left side of the neck. The patient did not seek medical attention after removing it himself. No neurological symptoms followed the incident. No cervical manipulation or other physical trauma occurred before current symptom onset. Magnetic resonance (MR) imaging showed features consistent with myelitis at the level of C4-Th3. At the level of C6-C7, a T1 and T2 hypointense lesion was noted. On computed tomography, this lesion was hyperdense and occupied the spinal canal and the left intervertebral foramen. It was deemed to be a glass fragment. Surgical removal was withheld because the fragment was clinically silent for 30 years, the risk of surgical removal would outweigh the benefits and the patient did not prefer surgical treatment. Acute demyelinating transverse myelitis was diagnosed and treated with methylprednisolone. 10 months later MR features of myelitis resolved and the patient's neurological condition improved. Our case shows that foreign bodies in the cervical spinal canal can remain asymptomatic for up to 30 years. In the case of a long asymptomatic retention period the need for surgical removal of a foreign body must be carefully evaluated, taking into account the probability that a foreign body is the cause of current symptoms, risk of a foreign body causing damage in the future, risk of damage to the spinal cord during removal, and probability of therapeutic success.