An optical imaging lens includes six lens elements positioned sequentially from an object side to an image side along an optical axis. The image-side surface of the first lens element has a concave portion in a vicinity of the periphery of the first lens element and the object-side surface of the sixth lens element has a convex portion in a vicinity of the periphery of the sixth lens element. Gaa is a sum of all five air gaps from the first lens element to the sixth lens element along the optical axis, T5 is a central thickness of the fifth lens element along the optical axis, and Gaa and T5 satisfy the equation Gaa/T5≤3.85.