A rear implement mounting frame construction for a tractor is disclosed. The construction comprises a pair of mounting frames attached respectively to right and left sides of a tractor body. Each of these mounting frames comprises a plate member having a plate thickness oriented along the right/left direction. Each mounting frame also includes a case mounting portion that is connected to a rear axle case of the tractor body and a vertical connecting portion formed rearwardly of the case mounting portion which connects a rear implement. A bent portion formed between the case mounting portion and the vertical connecting portion causes the vertical connecting portion to be disposed closer to the tractor body than the case mounting portion. A right/left distance between the vertical connecting portions is set smaller than a right/left distance between the case mounting portions.