Metallic tungsten film has been obtained by potentiostatic electrolysis in ZnCl2-NaCl-KCl (0.60:0.20:0.20, in mole fraction) melt containing WCl4 at 250 degrees C. The deposit obtained after the electrolysis at 0.02 V vs. Zn(II)/Zn for 3 h was ca. 0.5 mm thick and the surface was not smooth. On the other hand, addition of 4 mol % of KF to the melt gave a smooth metal deposit ca. 0.5 mm thick in the same condition as above. (c) 2005 The Electrochemical Society.