An optical imaging lens includes six lens elements disposed sequentially from an object side to an image side. The image-side surface of the first lens element comprises a concave portion in a vicinity of an optical axis. The third lens element has positive refracting power. The fourth lens element has positive refracting power. The image-side surface of the fifth lens element comprises a convex portion in a vicinity of the optical axis. The optical imaging lens as a whole has only the six lens elements having refractive power.