THE INVENTION RELATES TO THE PREPARATION OF LITHIUM, SODIUM AND QUATERNARY AMMONIUM CYUANOBROHYDRIDES. THESE COMPOUNDS ARE PREPARED BY MIXING SUBSTANTIALLY ANHYDROUS HYDROGEN CYANIDE WITH A SUBSTANTIALLY ANHYDROUS LITHIUM OR SODIUM OR QUATERNARY AMMONIUM BOROHYDRIDE AT A TEMPERATURE BETWEEN 0*C. AND 100*C. IN A SUBSTANTIALLY ANHYDROUS SOLVENT, SUCH AS TETRAHYDROFURAN, GLYME, DIGLYME, TRIGLME OR DIMETHYL FORMAMIDE OR MIXTURES OF THESE AT ATOMPHERIC PRESSURE. IF DESIRED. TO AVOID LOSS OF HYDROGEN CYANIDE, A PRESSURE OF FROM ABOUT 1 TO 5 POUNDS PER SQUARE INCH MAY BE USED. PREFERABLY, THE PREPARATION IS CARRIED OUT IN TWO STAGES (1) INTIALLY AT A TEMPERATURE BETWEEN ABOUT 10*C. TO ABOUT 35*C. UNTIL SUBSTANTIALLY ALL HYDROGEN HAS CEASED TO BE EVOLVED AND (2) THEN AT A TEMPERATURE BETWEEN ABOUT 35* C. AND THE BOILING POINT OF THE SOLVENT UNTIL ALL THE INTERMEDIATE PRODUCTS HAVE BEEN CONVERTED TO THE DESIRED CYANOBOROHYDRIDE.