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