In this paper the effect of surface sputtering with diamond - like carbon (DLC) on CaSO4 scale formation was investigated. Fouling runs were carried out under pool boiling conditions with heat fluxes of 100 - 300 kW·m-2 and a saturated CaSO4 concentration at 100℃. The results showed that surface sputtering with DLC reduces CaSO4 scale formation significantly.