Several studies have investigated the T-1 and T-2 relaxation time of choline, creatine and N-acetyl aspartate in cerebral white matter in normal human subjects. However, these studies demonstrate a large variation in T-1 and T-2 values. In the present study, relaxation times of choline. creatine and N-acetyl aspartate were determined in cerebral white matter in 15 control subjects (age 21 +/- 2 y, mean +/- SD) at 1.5 T. Using PRESS, seven or eight data points were obtained to fit the T-1 and T-2 relaxation curves to, respectively. The mean voxel size was 14 cm(3). The T-1 relaxation times of choline. creatine and N-acetyl aspartate were 1091 +/- 132 (mean + SID), 1363 +/- 137 and 1276 +/- 132 ins. The T-1 relaxation times were 352 52, 219 +/- 29 and 336 +/- 46 ins. respectively. Copyright (C) 2002 John Wiley Sons, Ltd.