An imaging lens for an image pickup device is formed of only three lens components of positive, negative, and positive refractive power, in order from the object side. A diaphragm stop is positioned on the object side of the lens component nearest the object side. Six lens component lens surfaces are aspheric. The lens component nearest the object side is biconvex with regard to the central areas of its two lens surfaces. The image-side surface of the lens component nearest the image side has a concave central area surrounded by a convex surface area. The middle lens component has one lens surface with a concave central area and one lens surface with a convex central area. The Abbe number of the central lens element and the ratio of the focal length of the imaging lens divided by the focal length of the object-side lens component satisfy specified conditions.