Juvenile hyaline fibromatosis is a rare autosomal recessive connective tissue disease first described in 1873 by Murray. Major diagnostic criteria are multiple cutaneous tumors and gingival hypertrophy; minor criteria include contractures, osteolytic lesions and a positive family history. After a normal perinatal period at the age of 6 months our 24 year old patient developed gingival hypertrophy. During the first months of life several skin coloured nodules had been noticed on the neck and in the perianal area. At the age of 15 months, these nodules began to appear more rapidly, both spontaneously and posttraumatically. The patient showed normal development, but the lesions progressed. By the age of 15 years, the patient had extensive deformities and was unable to walk and move by himself. Both his sisters and the unrelated parents had no lesions. Essential for the diagnosis are the clinical picture and the histology. Electron microscopy is helpful to support the diagnosis. Defective connective tissue proteins such as chondroitin, collagen and mucopolysaccharides are probably the pathological defect. A therapy is so far unknown.