A rear discharge mower (2) comprises: a first shaft (22); a first blade (21) which is rotated in unison with the first shaft (22); a second shaft (22) that is configured to be rotated in a direction opposite with respect to a rotational direction of the first shaft (22); a second blade (21) which is rotated in unison with the second shaft (22), a grass discharge passage being formed through which grass clippings are ejected in a rearward direction from the area between the first shaft (22) and the second shaft (22); a housing (3) which supports the blade shafts (22); and a transmission (4) which is accommodated in the housing (3) and which transmits power to the first and second shafts (22).