A new method for measuring formaldehyde released from cured urea formaldehyde resins under conditions favouring hydrolysis is described. The technique is devised for both industrial quality control and research and it is relatively fast, permits the independent control of water activity and temperature and guarantees the absence of leaching of resin ingredients. The aim of verifying the suitability of the method was persuaded through studying the effect of F: U molar ratio, type of UF concentrate, manufacturing technology, type and concentration of catalyst, type of formaldehyde-scavenging and acid-neutralising additives, on the hydrolytic stability of cured urea-formaldehyde resins. The fact that qualitatively similar results have been reported by other researchers using the Flask method, or versions of the WKI method confirms the reliability of the new technique.