INTRODUCTION: Dystonia is a prevalent movement disorder characterized by involuntary muscle contractions, and cervical dystonia is among the most common forms. This report presents a rare case of severe isolated cervical dystonia in a young male patient that progressed to type IV atlantoaxial rotatory subluxation, highlighting the clinical presentation and diagnostic challenges associated with this condition. CASE DESCRIPTION: A 27-year-old male patient presented with abnormal head posture and severe cervical pain. Clinical examinations revealed severe cervical muscle spasms and a unique head posture, as if he was looking at the tip of his right shoulder. Radiological evaluation revealed a type IV atlantoaxial rotatory subluxation. Despite initial attempt of close reduction under anesthesia, recurrence of the subluxation occurred, and surgical intervention was necessary. CONCLUSION: This case underscores the importance of thorough clinical evaluation and imaging in the diagnosis of isolated cervical dystonia, particularly given its potential to present with atypical features. These findings suggest that early recognition and intervention may be critical for preventing complications and improving patient outcomes.