This paper is a case report of a 53-year-old housewife with fibrosarcoma of the neck. On 27 August 1986, she was admitted to our hospital with discomfort on the right side of her throat and difficulty in swallowing. She had no history of radiation therapy to the neck. The tumor was below the right submandibular gland and was movable. No enlarged lymph nodes were palpated in the neck. The mean CT number of the tumor was 59.5 H.U. The tumor was almost circular and its surface was smooth. Upon operating, the tumor was observed to be connected to the greater cornu of the hyoid bone and the superior cornu of the thyroid cartilage. The tumor measured 50 x 42 x 35 mm and was well circumscribed but not encapsulated. The cut surfaces were generally fleshy, glistening and grayish-white. The tumor was composed of small amounts of collagen and reticulin, producing fairly uniform spindle cells arranged in interlacing bundles, forming a herring bone pattern. The tumor cell showed rather little atypism, but did show obvious mitotic activity. Thus, the tumor was diagnosed as well-differentiated fibrosarcoma. When the patient was last seen, in April 1989, there was no evidence of recurrence.