A flow responsive pressure regulating unloader suitable for use between a positive displacement fluid pump and a fluid consuming device connected to the pump. The unloader includes a housing having an inlet port connected to an outlet port, and a by-pass port. A fluid pressure regulating valve is connected between the inlet port and the by-pass port to limit the maximum fluid pressure at the inlet port. A flow responsive valve also is connected between the inlet port and the by-pass port. Fluid flow from the inlet port to the outlet port creates a pressure drop across an orifice. The pressure differential is applied across a piston to close the flow responsive valve. When flow from the outlet ceases, the pressures across the piston become equal and the fluid pressure on the flow responsive valve opens the valve to divert fluid to the by-pass port.