This report describes the cytological findings of a case of myositis ossificans in a 16-yr-old girl. Clinically and radiologically she was suspected to have a malignant soft tissue tumor. This was not confirmed by fine-needle aspiration cytology and a diagnosis of benign lesion, probably myositis, was given. This diagnosis was confirmed by histological examination. Diagn Cytopathol 1994; 10:41-43. (C) 1994 Wiley-Liss, Inc.