5-Hydroxy-3-pyrrolin-2-ones are regioselectively synthesized in a good yield under very mild conditions by tetracyanonickelate (0) ion catalyzed hydrocyanation of alpha-ketoalkynes, in the absence of hydrogen cyanide. The catalyst is prepared in situ in a basic aqueous medium by reduction of Ni(CN)(2) with CO in the excess of KCN. From the LR spectroscopy studies and by evaluation of catalytic activity of some cyanonickelates it is proposed that [Ni(CN)(4)](-4) anion is the active species in the process. A possible mechanism is suggested for the conversion of nickel cyanide to [Ni(CN)(4)](-4). The effect of the reaction variables, e.g.: reaction time, temperature, absorption of carbon monoxide, the concentration of potassium cyanide, water, substrate, and sodium hydroxide were also examined.