Fibrous dysplasia is a benign fibro-osseous lesion progressing with one or more bone involvements in the skeleton. Even though it is a benign tumor, it may potentially transform into a malignant one. While the most frequently involved zones in the head-neck zone include the maxilla, mandible, parietal, occipital, and temporal zones, the involvement of the ethmoid bone is rather rare. This article presents the case of a female patient who was diagnosed with fibrous dysplasia in the right ethmoid sinus based on the paranasal computerized tomography scan that was taken due to the symptoms of pain around the right eye, pressure, and a feeling of being pushed.