Abstract: A portable lawn and brush trimmer including an elongated tubular boom arm, motor assembly mounted at one end of the boom, a trimmer head mounted on the opposite ends of the boom arm, and two adjustment mechanisms, which allow the attitude of the trimmer head to be adjusted about two different axis in relation to the boom arm is disclosed. The adjustment mechanisms allow an operator to manually change the attitude and orientation of the trimmer's cutting plane to conform to the slope and contour of the terrain without the operator altering the natural balanced operating position of the trimmer or his body posture while maintaining the natural balanced orientation of the boom arm with respect to the operator and not the terrain being worked. One adjustment mechanism (pivot adjustment) allows the trimmer head to pivot in relationship to the boom arm between a number of manually selectable angular positions.