Calcific tendinitis of the longus colli is an inflammatory disease caused by calcium hydroxyapatite crystal deposition in the longus colli tendon of the prevertebral space. It is also known as retropharyngeal calcific tendinitis or prevertebral tendinitis. The typical imaging characteristics of this entity are calcifications on the superior insertion of the longus colli tendons at the C1-2 level and fluid collection in the retropharyngeal space. However, we introduce 2 case of acute longus colli tendinitis without definite calcification deposition on simple X-ray.Calcific tendinitis of the longus colli is an inflammatory disease caused by calcium hydroxyapatite crystal deposition in the longus colli tendon of the prevertebral space. It is also known as retropharyngeal calcific tendinitis or prevertebral tendinitis. The typical imaging characteristics of this entity are calcifications on the superior insertion of the longus colli tendons at the C1-2 level and fluid collection in the retropharyngeal space. However, we introduce 2 case of acute longus colli tendinitis without definite calcification deposition on simple X-ray.