Abstract: A pumping unit for actuating a linear reciprocable pump rod comprises a frame having a pair of spaced apart vertical guides for guiding vertical reciprocating movement of a traveling pulley assembly connected to a linear extensible hydraulic cylinder mounted on the frame directly under the pulley assembly. The pulley assembly includes two rotatable sheaves over which are trained, respectively, flexible cables which are anchored at their opposite ends to the frame and to a bracket connected to the pump rod. The arrangement provides a single purchase pulley system providing for a pump rod stroke length of twice the stroke length of the cylinder actuator. A hydraulic control system for reciprocating the cylinder includes a solenoid operated valve which is controlled by a cam actuated switch to alternately provide for conducting hydraulic fluid to and from the cylinder. The valve actuating switches are tripped by spaced apart cams mounted on a rod connected to the pulley assembly.