OBJECTIVE: To present an extremely rare case of progressive facial hemiatrophy. CASE REPORT: A 24-year-old female patient with progressive facial asymmetry presented at our clinic. The physical examination revealed atrophic subcutaneous tissue and muscle of the left side of her face. Computed tomography of the paranasal sinuses showed preserved bone structure and facial asymmetry due to the destruction of adipose tissue in the left cheek. Cranial magnetic resonance imaging showed no change in brain structure. The diagnosis of Parry Romberg syndrome was made and the patient underwent surgery for facial filling with methacrylate. FINAL COMMENTS: Parry Romberg syndrome (or progressive facial hemiatrophy) is an extremely rare disease of unknown etiology that mainly affects young women. The condition is characterized by slowly progressive atrophy of the face (unilateral in 95% of cases), usually involving skin and subcutaneous tissue. Bones and muscles are affected in more severe cases. The diagnosis is clinical, confirmed by imaging exams. Treatment involves correction of the deformity with facial silicone injections or bovine collagen, inorganic implants, and reconstruction with adipose tissue, muscle and pedicle flaps. More severe cases may require osteotomy or the use of bone grafts and/or synthetic materials (e.g., silicone, methacrylate, hydroxyapatite).