Calcific retropharyngeal tendonitis is an under-recognized cause of acute cervical pain produced by inflammation of the longus colli muscle. Although the clinical presentation may mimic more serious disorders, the diagnosis can be established radiographically by identification of prevertebral soft tissue calcification and swelling. Six patients with typical signs and symptoms of retropharyngeal tendonitis are presented. All were evaluated with plain films, four with CT and one with MRI. The pathognomonic finding of amorphous calcification anterior to C1-2 with associated asymmetric soft tissue swelling was clearly demonstrated by CT. Diffuse swelling of the longus colli muscle was shown as prominent high signal in the prevertebral region by T2 weighted MRI.