A sixty-nine-year old woman exhibited during her lifetime many of the characteristics of osteogenesis imperfecta, including multiple fractures with dwarfism and deformity, hearing failure, and blue sclerae. Otosclerosis was related to fixation of the stapedial foot plates in the inner ears. The osseous structure consisted of mature lamellar bone of deficient quantity. The authors suggest a defect in matrix production by the osteoblasts as the basic defect.