General principles involved in electrochemical machining process, have been discussed. Electrochemical machining of metals follows Faraday's Laws and the electrochemistry shows that the process is controlled by many factors such as surface film free workpiece, proper gap width control, tool design, flow rate of electrolyte, suitable electrolyte and its temperature and proper insulation of the parts which are not to be machined. The method is feasible where high wear due to difficult machining materials is involved. Electrochemical machining is a process which would machine even the hardest alloy with the same ease as any soft metal. It should also provide machining and polishing simultaneously. However the surface obtained in ECM is stress, free and Represents the true fatigue properties. Usually the fatigue properties lowered in ECM, could be compensated by post machining process, such as honing and shot peening. The choice of ECM would depend upon the power costs and tool design etc. and at present it may seem feasible only with such metals and alloys which are extremely difficult to machine by conventional methods. However the use of ECM in Pakistan may be relatively feasible because of relatively lower rates of electric power and the higher costs involed in the import of lathe tools etc. The complete economics about this is however not available.