A photographing optical lens system includes six lens elements. The six lens elements are, in order from an object side to an image side, 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. The second lens element has negative refractive power. The third lens element with negative refractive power has an image-side surface being concave in a paraxial region thereof. The fifth lens element has an image-side surface being concave in a paraxial region thereof. The sixth lens element has positive refractive power.