In this work, glass-fiber-supported activated carbons (GFACs) were prepared by KOH activation using phenolic resin. Two different preparation methods were chosen: (a) filling and (b) impregnation methods. The structural properties of the GFACs studied were characterized by using N-2 adsorption isotherms at 77 K and transformed models, such as the DR equation and the alpha(s)-plot. A scanning electron microscope (SEM) was also used to investigate the external pore structure of the resulting carbons. The specific surface areas and pore volumes for both methods increased with increasing content of KOH. However, the pore evolution for the filling method was superior to that for the impregnation method. DR plots for all samples showed a good linearity at low relative pressure. Also, all samples displayed a slight upward deviation at the linear portion of the alpha(s)-plots, indicating the presence of mesopores and external surface area. SEM studies showed that GFACs possessed a well-developed pore structure and exhibited a change in the pore evolution according to the preparation conditions. (C) 2003 Elsevier Inc. All rights reserved.