A simple, rapid and cost-effective method for the removal of arsenic from water has been developed. Both As(III) and As(V) could be removed quantitatively by treating the polluted water with ferrous sulphide in granular form. Ferrous sulphide is cheap and easily available commercially and very effective for this purpose. Various factors influencing the treatment procedure have been studied and the mechanism of the removal process has been discussed. It has the additional advantage that the heavy metals like Pb, Hg, Cu, etc. that form insoluble sulphide are also removed along with arsenic. Analysis of arsenic content in the treated water by spectrophotometry and neutron activation analysis suggests that the method could successfully bringdown the concentration of arsenic below the permissible limit of 10 mug/L as recommended by WHO.