An imaging lens assembly includes, in order from an object side to an image side, a first lens element, a second lens element, a third lens element, a fourth lens element, a fifth lens element and a sixth lens element. The first lens element and the fourth lens element have positive refractive power. The second lens element with positive refractive power has an image-side surface being convex in a paraxial region thereof. The fifth lens element has an object-side surface and an image-side surface being both aspheric. The sixth lens element has an image-side surface being concave in a paraxial region thereof, wherein the image-side surface thereof has at least one convex shape in an off-axial region thereof, and an object-side surface and the image-side surface thereof are both aspheric. The imaging lens assembly has a total of six single and non-cemented lens elements.