The purpose of this study was to describe a trigeminal neuropathy caused by the perineural spread of an amyloidoma. A 62‐year‐old woman had an amyloidoma of the Gasserian ganglion that was hypointense on T2‐weighted images; the lesion was enhanced by gadolinium on thin‐slice magnetic resonance imaging. There was no evidence of systemic amyloidosis or underlying inflammatory or neoplastic disorders. Her blink reflex and thin‐slice magnetic resonance imaging demonstrated that the right trigeminal nerve was involved. A rare trigeminal neuropathy resulted from the perineural spread of a primary amyloidoma that was difficult to detect by conventional magnetic resonance imaging. Muscle Nerve, 2010