Provided is an exhaust-heat recovery power generation device which is small in size, low in cost, and capable of recovering heat from heating mediums having different temperatures. The exhaust-heat recovery power generation device comprises: a plurality of first exhaust-heat recovery units (5), second exhaust-heat recovery units (11), and third exhaust-heat recovery units (15) which are disposed in parallel in an organic medium path (23) of working mediums to evaporate the working mediums by using the heating mediums having different temperatures; a power turbine (17) which comprises a single radial turbine wheel and converts, into rotational power, turning energy of the working mediums from the first exhaust-heat recovery units (5), the second exhaust-heat recovery units (11), and the third exhaust-heat recovery units (15) introduced from different axial directions; a power generator (19) which generates power by using the rotational power of the power turbine (17); and a compressor (21) which compresses the working mediums which have passed through the power turbine (17).