A notebook computer with a height-adjustable display unit is disclosed. The notebook computer includes a main unit, a display unit, and a height-adjusting mechanism. The height-adjusting mechanism includes a saw-toothed arm, a channel, and a locking mechanism. The saw-toothed arm is rotationally coupled to the main unit. The channel is fixed in the display unit and movably accepts the saw-toothed arm therein. The locking mechanism lock or unlock the movement of the saw-toothed arm in the channel. The height-adjusting mechanism affords adjustable support for the display unit. The height of the display unit can be adjusted as required.