Cerebrotendinous Xanthomatosis(CTX) is an uncommon autosomal recessive disorder in which there is accumulation of cholestanol in tissues such as lens, tendons and nervous system. It is clinically characterized by progressive neurological and neuropsychiatric dysfunction with ataxia, spasticity, and peripheral neuropathy, associated with bilateral premature cataracts, tendon xanthomas, premature atherosclerosis and pulmonary dysfunction. Deficiency of the mitochondrial enzyme sterol 27-hydroxylase (CYP27 gene) is implicated in the pathogenesis. Two cases of CTX with similar history in the siblings, are being reported. One of them had tendon swelling, cataract, polyneuropathy, low IQ, ataxia, pyramidal tract involvement with electrophysiological abnormalities in the form of demyelinating neuropathy in nerve conduction tests and prolonged N19 latency in somato sensory evoked potential (SSEP) studies. The second patient had tendon swelling, low IQ, cataract, polyneuropathy, ataxia, involuntary movements, pyramidal signs with evidence of demyelinating neuropathy. She improved partially with Chenodeoxycholic acid (CDCA) and simvastatin. Histopathology of the tendon swelling in both the cases revealed disruption of the fibrocollagenous bands of the tendon by masses of xanthomatous cells containing foamy cytoplasm amassed around cholesterol clefts and multinucleated giant cells. Accurate and early diagnosis is important because of the therapeutic potential