Congenital cholesteatoma of the middle ear is frequently seen in younger children including infant. By contrast, that of the petrous bone is rarely seen in younger children. We report an exceptional case occurring in 23-month-old infant who presented with unilateral facial nerve paralysis at about 18-month-old. Computed tomography and magnetic resonance imaging revealed congenital cholesteatoma measuring approximately 2 cm in the area of the right geniculate ganglion. The mass was completely eradicated via the middle fossa approach, which allowed for preservation of hearing. The facial nerve maintained intact during surgery and paralysis showed partial recovery after the operation. To our knowledge, the present case seems to be the youngest case of congenital petrosal cholesteatoma reported, and also demonstrates congenital petrosal cholesteatoma could exhibit facial nerve paralysis in early childhood.