Background <p>Polyneuritis cranialis is a rare condition than can be caused by various diseases. We report the first case of multiple cranial nerve paralysis resulting in neurotrophic keratopathy with corneal ulceration as a sequel of polyneuritis cranialis due to actinomycosis.</p> Case presentation <p>An 84-year-old German woman developed corneal ulceration with a high risk of perforation because of neurotrophic keratopathy due to polyneuritis cranialis. Actinomycosis of a wisdom tooth causing polyneuritis cranialis was detected on computed tomography and magnetic resonance imaging and was treated with systemic antibiotics. Penetrating keratoplasty with simultaneous amniotic membrane transplantation was performed successfully after conservative treatment failure.</p> Conclusions <p>To the best of our knowledge, we report on the first case of multiple cranial nerve failure due to actinomycosis and requiring ophthalmological intervention.</p>