An optical imaging lens includes five lens elements arranged from an object side to an image side in a given order along an optical axis of the optical imaging lens. The object-side surface of the second lens element has a convex portion in a vicinity of its periphery, the object-side surface of the third lens element has a convex portion in a vicinity of the optical axis, the object-side surface of the fourth lens element has a concave portion in a vicinity of its periphery, the optical imaging lens as a whole has only the five lens elements, and an effective system focal length is EFL, an air gap between the second lens element and the third lens element along the optical axis is G23, a central thickness of the third lens element along the optical axis is T3, and EFL, G23 and T3 satisfy the equation

4.89≤EFL/(G23+T3)≤5.88.