Nanosized amphiphilic polyurethane (APU) particles synthesized on the basis of amphiphilic urethane acrylate nonionomers could solubilize phenanthrene within their hydrophobic interiors in the same way that surfactant micelles do in the aqueous phase. At low concentrations of APU or Triton X-100 in the aqueous phase, APU particles exhibited a greater extraction efficiency of sorbed phenanthrene than did the Triton X-100 aqueous pseudophase. At higher APU particle and Triton X-100 doses in aqueous solution, the extraction efficiency of the APU aqueous solution was almost same as that of the Triton X-100 aqueous solution, even though APU particles exhibited a lower solubilizing efficiency than Triton X-100 micelles in the absence of aquifer soil. This was because APU particles have a relatively low degree of sorption on aquifer sand because of their chemically crosslinked structure. APU particles could be also recovered at a rate of 100% through an ultrafiltration process at a greater pore size of the separation membrane, which would make soil washing with APU particles more economical and useful in practical applications.