Introduction For more than a decade, otologists have been occupied with devising ingenious and complicated operations to relieve deafness caused by otosclerosis. They have lost sight of the principle that the scientific method of investigation of disease is to endeavour to discover the cause and thereafter to devise a cure based on precise knowledge of etiology and pathology. This statement by Hall and Ogilvie (1961) characterizes very well the present state of otosclerosis research, although the search for operative techniques has been going on for many decades. Lately, an attempt has been made by Hall and collaborators to establish a connection between otosclerosis and osteogenesis imperfecta, an idea first considered by Weber some time ago. Under these circumstances, a renewed study of the histological changes in the temporal bones in osteogenesis imperfecta congenita, which for purely morphological reasons alone would have been hardly worthwhile, seemed justified. Report of Cases Case