Introduction. Subacute sclerosing panencephalitis is progressive, fatal encephalitis caused by a persistent defective measles virus in the central nervous system. The diagnosis is based upon characteristic clinical manifestations, the presence of characteristic periodic EEG discharges, and demonstration of elevated antibody titer against measles in the plasma and cerebrospinal fluid. There has been no correlation between the clinical status and the MRI findings. Methods. We performed single voxel magnetic resonance spectroscopy (MRS) on white matter areas that appeared normal or abnormal on conventional MRI in three patients with different clinical stages. Results. N-acetyl aspartate:creatine ratios were decreased and choline:creatine ratios were increased in white matter lesions in the late stages of the disease. A lactate peak was observed in a patient in the last stage of the disease. Increased myoinositol:creatine ratio was seen in white matter areas on conventional MRI and in the white matter lesions at early stage of the disease, before neuronal loss.