An optical imaging lens includes first, second, third, fourth, fifth, and sixth lens elements, each having an object-side surface facing toward an object side and an image-side surface facing toward an image side. The image-side surface of the first lens element includes a concave portion in a vicinity of the optical axis and a concave portion in a vicinity of a periphery of the first lens element. The image-side surface of the second lens element includes a convex portion in a vicinity of the optical axis. The image-side surface of the third lens element includes a concave portion in a vicinity of a periphery of the third lens element. The object-side surface of the fourth lens element includes a concave portion in a vicinity of the optical axis. The optical imaging lens as a whole has only the six lens elements having refractive power.