Background: In children, when unresponsive neck rigidity and distress are observed after ear, nose and throat (ENT) surgical treatment or nasopharyngeal inflammation, Grisel’s syndrome should be suspected. This is a rare syndrome involving non-traumatic rotatory subluxation of the atlantoaxial joint. Conservative management with external cervical orthoses and empirical antibiotic, muscle relaxant and analgesic therapy should be the first choice of treatment. Surgical stabilization is indicated when high-grade instability or failure of stable reduction are observed. The instability is graded according to the classification system devised by Fielding and Hawkins. Several recommendations for treatment are available in the literature, but there are no common guidelines. In this paper, the authors discuss the need for prompt diagnosis and treatment considerations. Case Description: Five children with Fielding type I–III rotatory subluxation are reported. Three patients were treated with a cervical collar, and one patient was treated with skull traction and sternal–occipital–mandibular immobilizer (SOMI) brace application. Surgical treatment was necessary for one patient after failure of initial conservative management. The intervals between the onset of torticollis and radiological diagnosis ranged from 12 to 90 days. A relationship between an increased grade of instability and delayed diagnosis was observed. Conclusion: In children with painful torticollis following ENT procedures or nasopharyngeal inflammation, Grisel’s syndrome should always be suspected. Cervical magnetic resonance imaging (MRI) allows prompt and safe diagnosis, and a three-dimensional computed tomography (CT) scan provides better classification of the instability. Surgery, which is indicated in cases of high-grade instability or failure of conservative treatment, may be avoided with prompt diagnosis.