Four dichlorophenol (I) isomers were adsorbed from aq. solns. on optionally surface-oxidized C nanotubes to det. the adsorption kinetics and equil. The I were better adsorbed on unmodified C tubes. The adsorption was fast and its kinetics was fitted with the pseudo-second-order model. The adsorption isotherms were well described by Langmuir equation. The 2,5-1 showed the highest and the 2,4-1 the lowest adsorption capacity.