A capillary electrophoretic method (CE) with ultraviolet absorption detection for ba- clofen in human plasma was developed. The separation was obtained by CE with 50 mM borate buffer at pH 9, followed by detection with an ultraviolet detector at 225 nm. The plasma samples were deproteinized with acetonitrile to remove proteins and to induce sample stacking. With stacking, the limit of detection (LOD) for baclofen in plasma was 0.2 µM. A calibration curve ranging from 1.5 to 300 µM showed to be linear. Both the within-day and day-to-day reproduci- bility and accuracy were less than 15% and 8%, respectively. The recoveries of baclofen in hu- man plasma were 99.6 - 103.3%.