An apparatus and a method for executing a mouse pointer function in a portable terminal equipped with a camera are disclosed. The method includes: capturing an external image signal by a camera module; sampling the external image signal and converting a sampled image signal into image data; mapping a group of pixels of the image data generated by the sampling to a group of pixels of an image sensor for each unit pixel on a one-to-one basis; detecting coordinate values of image data including a point light source in the group of the mapped pixels; determining if a point light source is actually included in the detected coordinate values of the image data; and displaying the detected coordinate values of the image data determined to include the point light source on a screen.