Multiple sclerosis is a chronic demyelinating disease of the central nervous system. Tumor-like manifestation of multiple sclerosis is one of the rare clinical variants and it is frequently misdiagnosed. This is a report on a 45-year-old man who presented with right-sided hemiparesis. Initial computed tomography and magnetic resonance imaging studies of the brain revealed a large hyperintense signal lesion in the left hemisphere surrounding the cerebral edema. Low grade glioma was among the likely differential diagnoses. The patient underwent surgery. Brain biopsy showed demyelination. Lumbar puncture was performed and cerebrospinal fluid was positive for intrathecal synthesis of immunoglobulins. Other findings were compatible with the unusual form of multiple sclerosis. This case report illustrates a demyelinating process mimicking tumor lesions of the brain and it is of high importance to consider the diagnosis of multiple sclerosis on differential diagnosis of a tumor-like lesion of the central nervous system.