1116-1119The kinetics of hydrolysis of urea has been studied in 0.5 to 3.0 mol dm- 3 sodium hydroxide solution at different temperatures. Urea hydrolysis follows an irreversible first order consecutive reaction path: The variation of k1obs with [alkali] is linear at [OH-]=5.0 to 1.5 mol dm-3, thereafter a sharp increase in the reaction rate is observed for first step hydrolysis of urea. The second step rate constant (k2obs) is found to be independent of [alkali]. Hydrolysis of urea in alkaline medium follows an elimination-addition mechanism. The reaction does not proceed through the formation and decomposition of tetrahedral intermediate. Sodium cyanate hydrolysis obeys an irreversible pseudo-first order kinetics. [OH-] has no significant effect on the rate constants. The following rate equations have been derived for the two step hydrolysis of urea. On the basis of observed data, probable mechanisms have been proposed.<br