The characteristic features of Madras motor neuron disease (MMND) are onset in the young in the first two decades, sporadic occurrence, facial and bulbar paralysis, sensorineural hearing impairment, asymmetrical weakness of limbs and pyramidal signs with a slow progression. The majority of the cases reported are from South India. MMND variant has the additional features of optic atrophy and cerebellar signs. We are reporting a 48 year old female of MMND who had persistent fasciculations of chin, with electromyographic features of fasciculations and fibrillations in mentalis muscle. Chin fasciculations, a rare clinical feature, is now described for the first time in Madras motor neuron disease adding a new feature to the clinical constellation of symptoms.