Abstract: A motorcycle windshield assembly includes two frame units coupled to a windshield. Each frame unit includes a pair of corresponding adjusting elements jointly enclosing an end of an installation rod. Each pair of the adjusting elements are fitted into receiving spaces of a corresponding pair of left and right covers such that teeth formed on each pair of the adjusting elements mesh with teeth formed in the corresponding pair of left and right covers. Each pair of the left and right covers have a side provided with guide grooves for receiving a sliding element coupled to the windshield. Thus, the windshield coupled to the frame units can be conveniently raised, lowered, or tilted to provide the desired shielding effect. The motorcycle windshield assembly is flexibly adjustable in height and tilt angle and is collapsible when not in use.