The diagnosis of multiple sclerosis (MS) is based on clinical, radiological and biological findings. A misinterpretation of non specific clinical and radiological findings may contribute to misdiagnosing MS mimickers such as inherited leucoencephalopathies. Mrs NS, a 28 year-old woman was referred to our unit for vertigos and gait disturbances evolving since 15 days. Neurological assessment showed central vestibular syndrome and deep sensory alterations. Brain and spinal cord MRI showed non enhancing T2 and Flair hyperintensities in the parieto-occipital periventricular white matter, cerebellar pedoncules and the cervical portion of the spinal cord. Lumbar puncture showed oligoclonal bands in cerebrospinal fluid. The visual evoked potentials showed bilateral optic demyelinating neuropathy. Biochemistry revealed adrenal insufficiency. The diagnosis of adrenoleucodystrophy in a carrier woman was plausible all the more we noted high Lactate-to-pyruvate ratio. However the dosage of Very-Long-Chain-Fatty-Acids was normal. Hence, the diagnosis of MS was made. The patient received five days pulsed-methylprednisolone and experienced rapid improvement. Many patients are misdiagnosed with multiple sclerosis, and might be given disease modifying therapies while they suffer from metabolic or systemic disorders mimicking inflammatory demyelinating diseases. There are many overlapping factors mainly: inflammation which is the underlying mechanism of X-linked adrenoleucodystrophy (X-ALD), demyelinating optic neuritis, the presence of oligoclonal bands in CSF which were reported in X-ALD patients. In our case we ruled out the diagnosis of X-ALD but this should be considered in patients with atypical MRI features or family history of adrenomyelopathy mainly in males.