The present invention relates to a process for reusing the overspray obtained when spraying water dilutable two-component polyurethane coating compositions containing a polyisocyanate and a compound containing isocyanate reactive groups by(i) collecting the overspray and optionally diluting it with water,(ii) simultaneously with or after step (i), reacting the overspray, optionally in the presence of emulsifiers, with compounds which are more reactive with isocyanate groups than both water and the compounds containing isocyanate reactive groups and(iii) reusing the resulting aqueous solution or dispersion of the chemically modified overspray in a one- or two-component, chemically and/or physically drying coating composition, optionally after adjusting the spray viscosity of the coating compositions to a suitable spray viscosity by either removing or adding water and optionally after the addition of additives.