We found that in-situ preparation of Ni2B with the addition of excess NaBHa was--6ff--ective in the extensive dechlorination of DDT (DENNIS-and COOPER, 1975), heptachlor and chlordane (DENNIS and COOPER, in press). Similar systems have been used to reductively dehalogenate aromatic systems (EGLI, 1968) and as a site specific method for deuteration (BOSIN, et a l . , 1973). This catalytic system was found to rapidly and comp-Te~ly dechlorinate lindane (the gamma isomer of 1,2,3,4,5,6 hexachlorocyclohexane) to benzene, cyclohexene, cyclohexane and chloride ions. In a similar reduction of lindane described by Bieniek e t a l . (1970), lindane, Co2B and an excess of NaBH4, in various solvents, produced tetrachlorocyclohexane as the major product.