A rotary fluid machine includes a first operating part (49) and a second operating part (57), which are groups of axial piston cylinders, wherein a rotary valve (61) for controlling the intake and discharge of a working medium to and from the first and second operating parts (49, 57) is formed from a first valve part that has a flat sliding surface (68) perpendicular to a rotational axis (L) of the rotor (27) and controls the intake and discharge of the working medium to and from the first operating part (49), and a second valve part that has a cylindrical sliding surface (71) centered on the rotational axis (L) of the rotor (27) and controls the intake and discharge of the working medium to and from the second operating part (57). Since the intake and discharge of the working medium to and from the first and second operating parts (49, 57) are controlled by the common rotary valve (61), the size of the rotary fluid machine can be reduced.