Abstract: Dilute aqueous urea solutions, contaminated with oil-solvent solution and obtained as filtrate or centrifugate in a urea dewaxing process of the type where a concentrated aqueous solution of urea is employed to form the wax-urea adduct, are purified by admixing the contaminated dilute aqueous urea solution with 1-25, preferably 2-5 volumes of solvent per volume of oil-solvent solution contamination, filtering the mixture, settling the mixture into two liquid phases, a substantially uncontaminated aqueous urea solution and an oil-solvent solution, and separating the two phases.