The authors studied 20 patients with subacute sclerosing panencephalitis (SSPE) to investigate the correlations between MRI, magnetic resonance spectroscopy (MRS), and clinical status. MRI findings did not correlate with clinical status. By contrast, all patients had reductions in N-acetyl aspartate (NAA) and increase in myoinositol (mI) (p < 0.01), and NAA and mI concentrations correlated with clinical severity (p < 0.05). During follow-up, NAA continued to decline. H-1-MRS may be a useful measure of disease severity and progression in SSPE.