Objects: A rare case of cerebellopontine angle arachnoid cyst leading to congenital peripheral facial palsy was presented.
Clinical presentation: A 1-year-old girl presented with peripheral facial paralysis since birth. Computed tomography and magnetic resonance imaging revealed left cerebellopontine angle arachnoid cyst causing moderate displacement of the brain stem.
Intervention: Retrosigmoid suboccipital craniotomy was performed and microsurgical resection of the cyst wall and fenestration of the cyst to the basal cisterns were achieved.
Conclusions: Cerebellopontine angle arachnoid cyst should be considered as a potential cause of congenital peripheral facial palsy.