A natural surfactant, β-cyclodextrin, was used for flushing in order to remove phenanthrene or naphthalene through a sand-packed soil bed. Equilibrium state and time-variant behavior of the hydrophobic compounds in the bed were analyzed to find out how solubilization was related to external flow and adsorption/desorption from soil matrix. Phenanthrene was more effectively eluted than naphthalene propably due to its higher hydrophobicity.