An optical imaging lens assembly includes five lens elements which are, 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 and a fifth lens element. The first lens element has an image-side surface being concave in a paraxial region thereof. The second lens element with negative refractive power has an image-side surface being concave in a paraxial region thereof. The third lens element with positive refractive power has an image-side surface being convex in a paraxial region thereof. The fourth lens element has positive refractive power. The fifth lens element has negative refractive power.