Congenital cholesteatoma is a rare but well-documented disease which can be defined as a collection of squamous epithelium found behind an intact tympanic membrane in the absence of previous otorrhea, Perforation or otologic procedures. It is thought to represent a developmental error in which epidermoid formation fails to involute. We present a case of huge over the lateral semicircular canal and the oval window niche was noted. This hump displaced the fallopian canal and the semicircular canal inferiorly. Medial to the hump, cholesteatoma extended along an air cell tract from epitympanum. The facial nerve was exposed in the proximal portion of the tympanic segment. The tensor tympani muscle was exposed widely to its distal part.