Abstract: In a so-called radial cell for unilateral electroplating of a moving metal strip, the strip as the cathode is in contact with an electrically conductive peripheral surface of a rotating cathode roller. An anode concentric with the roller over a part of the roller circumference is located at a distance from the strip so as to form a slot into which electrolyte is supplied. It has been found that the electrolytic process is improved in uniformity and speed if the electrolyte is supplied only at the entrance end of the slot in the direction of strip movement so that the electrolyte flows turbulently and generally unidirectionally through the slot to the exit end thereof and at a rate such that the average velocity of the electrolyte through the slot is at least 75% of the linear strip velocity. The angular length of the slot can be less than 180.degree.. Preferably the average velocity of the electrolyte through the slot is at least equal to the linear strip velocity.