A grass mower includes a cutting height adjustment mechanism for adjusting a cutting height of a mower unit via a lift link mechanism. The cutting height adjustment mechanism has a cutting height control grip disposed upwardly of the fender unit and on one outer side of the driver's seat in the vehicle body transverse direction, a cam body disposed downwardly of the fender unit and closer to a center of the vehicle body in the vehicle body transverse direction than the cutting height control grip, a rotational rod extending obliquely through the fender unit and connecting the cutting height control grip with the cam body, and a stopper body for selectively determining a cutting height of the mower unit in association as it comes into contact with one of a plurality of contact faces formed in the cam body.