The principal objectives of this research were (1) to identify activated pore structure and surface chemistry characteristics that assure the effective removal of trace organic contaminants from aqueous solution, and (2) to develop a procedure to predict the adsorption capacity of activated carbons from fundamental adsorbent and adsorbate properties. To systematically evaluate pore structure and surface chemistry effects on the adsorption of organic micropollutants from aqueous solution, a matrix of activated carbon fibers (ACFs) with three activation levels and four surface chemistry levels was prepared and characterized. In addition, three commercially available granular activated carbons (GACs) were studied to verify whether correlations developed for the ACF matrix are valid for adsorbents that are typically used for water treatment. BET surface area, pore size distribution, elemental composition, point of zero charge and infrared spectroscopy data were obtained to characterize the adsorbents. The results showed that the ACF matrix prepared in this study permits a fairly independent evaluation of surface chemistry and pore structure effects on organic contaminant adsorption from aqueous solution. Methyl tertiary-butyl ether (MTBE), a relatively hydrophilic adsorbate, and trichloroethene (TCE), a relatively hydrophobic adsorbate, served as adsorbate probes. To evaluate the effects of natural organic matter (NOM) on MTBE and TCE adsorption capacities, isotherm experiments were conducted in ultrapure water and Sacramento-San Joaquin Delta water. With respect to surface chemistry, both single-solute isotherms and isotherms in the presence of NOM indicated that hydrophobic adsorbents more effectively removed TCE and MTBE from aqueous solution than hydrophilic adsorbents. Enhanced water adsorption on polar surface sites explained the poorer performance of the hydrophilic adsorbents. Based on the elemental composition of the low-ash carbons evaluated in this study, act.