A microreflectometer system to detect micrometer-sized pinholes in specularly reflecting films has been developed. A modified compact disk player serves as an autofocusing reflectometer, with a feedback-stabilized source and a spot size on the order of 1 μm. Pinholes can be identified by the drop in signal where the reflective layer is missing. Total pinhole area in a scanned region can be determined most simply by selecting an appropriate threshold in the reflected signal (below which the presence of a pinhole is indicated), and counting the number of pixels on either side of the threshold. Additionally, changes in overall reflectance, such as those caused by the growth of a uniform oxide layer on a thin metal sample, can be detected independently of pinhole formation. This information will be of great use in studying the environmental degradation of metal and rare-earth/transition-metal (RE–TM) alloy films and the effectiveness of various protective overlayers.