Objective. The appearance of trigeminal neuralgia in infancy is exceptional. Trigeminal neuralgia as the only manifestation of a Chiari malformation is also infrequent. We present the case of a patient with a Chiari type I malformation ill which the only symptom was the presence of trigeminal neuralgia since infancy. We have found ilo similar cases in the literature, Clinical case. A 39 year old man with no significant clinical history complained of brief recurrent episodes of pain in the right maxillary region, compatible with trigeminal neuralgia since the age of eight. The frequency, duration and intensity of these episodes had progressively increased. The only unusual finding on physical examination was a sluggish right corneal reflex. Cranial MR showed descent of the cerebellar tonsils to below the level of the posterior arch of the atlas, together with slight descent of the brainstem. These findings are characteristic of a Chiari type I malformation. The symptoms rapidly disappeared when treatment was started with carbamazepine. Conclusion. In exceptional cases, trigeminal neuralgia may present in infancy and be the only manifestation of a Chiari malformation.