The present invention provides an imaging lens assembly including, in order from an object side to an image side: a first lens element with positive refractive power having a convex object-side surface; a second lens element with negative refractive power; a third lens element with negative refractive power; a fourth lens element with positive refractive power having a convex object-side surface; a fifth lens element having a concave image-side surface, at least one inflection point being provided on the fifth lens element; and an aperture stop disposed between an imaged object and the third lens element. Such an arrangement of optical elements can effectively improve the image quality of the system and enable the imaging lens assembly to maintain a compact form. When the aperture stop is disposed near the object side, the telecentric feature is emphasized, resulting in a shorter total track length. When the aperture stop is disposed near the third lens element, the emphasis is on the wide field of view, and such an aperture stop placement helps to effectively reduce the sensitivity of the imaging lens assembly.