Introduction Very shortly after the first demonstration of laser action by Maiman in 1960, it was apparent that the laser could be an excellent source for photocoagulation. The characteristics of the laser which are of particular value in photocoagulation are the great energy output in a short time interval, its monochromatic nature, and the narrow beam spread. The successful application of laser technology to medical problems requires that suitable instrumentation be developed. The design of the equipment must permit the physician to function efficiently and also must provide safety both to the patient and to the operator. Furthermore, extensive experimental studies are necessary before a new process, such as the laser, can be applied to clinical situations. In this report the technique of laser photocoagulation and the results obtained will be described. There is also included a description of instrumentation which has been used clinically and found to be suitable