The invention concerns an arrangement for controlling a hydraulic actuator (10) in a working device (42), which arrangement includes one or more hydraulic actuators arranged to drive a moving work element (43) belonging to the working device (42), which hydraulic actuator (10) includes two or more cylinder portions (11, 12) arranged inside relative to each other, i.e. an inner cylinder portion (12) and an outer cylinder portion (11), each of which cylinder portions includes a piston (13.1, 13.2) and a piston rod (14.1, 14.2) arranged to form an operating element (15, 16), a cylindrical part (17.1, 17.2), inside which the operating element is arranged, and the piston (13.2) of which inner cylinder portion (12) is arranged inside the piston rod (14.1) of the outer cylinder portion, and which piston rods of the operating elements are arranged to protrude partly outside the actuator; chambers (A, B) arranged to be formed in each cylinder portion; a pressure-medium feed arrangement (25, 26) to create the working m
