The reproducibility of single-voxel spectroscopic measures in a stable schizophrenic patient population is reported. Spectra acquired 1 week apart, in the left frontal white matter and left caudate nucleus of 12 patients, were analyzed using both frequency and time-domain techniques. No significant change in mean concentrations for N-acetylaspartate (NAA), choline (Cho), and creatine (Cre) were found between sessions. Variation from scan to scan was low for the left frontal white matter, with coefficients of variation (CV) < 5% for all three metabolites. NAA measures from the left caudate nucleus had similar reproducibility (CV = 5%), but Cho and Cre were poorer by comparison (CV = 16-18%). The two methods used for spectral analyses produced similar results, indicating that both techniques are appropriate. These results extend previous studies of healthy, normal subjects, and establish that it is possible to obtain reliable measures of brain metabolites in clinical populations.