A benign chondroblastoma of the left maxillary sinus developed in a 14-year-old girl. Roentgenographic examination showed an expanding, well-defined, calcified tumor. Facial and skull chondroblastomas may be related to primary or secondary centers of enchondral ossification, and therefore they may derive from the cartilage of growth plates [3]. Initial biopsy was inconclusive, but after surgical removal a histological diagnosis was made.