A new surface preparation method was devised for assessing intracochlear vessels and sensorineurepithelium. The method is a combination of the conventional osmic acid stained surface preparation method and a surface preparation technique with injection of Prussian blue and decalcification of the cochlea. Such a combination preserves most advantages of each and eliminates many of the disadvantages. To preserve the delicate sensory and nervous structures we examined variations of the preparation, paying particular attention to fixation, staining, and decalcification procedures and solutions. Varying the preparation had a less marked effect on external wall structures than on the basilar membrane; the primary changes consisted of variation in staining contrast. The method proved useful for demonstrating the normal anatomy and pathological changes in cochlear vasculature and in sensorineural and supporting structures of the labyrinth in light and phase contrast microscopy at moderate magnifications.