An optical imaging lens includes 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 from an object side to an image side in order along an optical axis. The first lens element to the sixth lens element each include an object-side surface and an image-side surface. The first and second lens elements are made of plastic material. The image-side surface of the third lens element has a concave portion in a vicinity of the optical axis. The fourth lens element has negative refracting power. The object-side surface of the fourth lens element has a concave portion in a vicinity of the optical axis. The object-side surface of the fifth lens element has a concave portion in a vicinity of the optical axis. The sixth lens element is made of plastic material.