In the last issue ofMedical Teacher, Dr Jack Marshall provided an overview of the methods being used to teach students basic clinical skills and to evaluate their performances (Medical Teacher, 1979,1, 190–194). Here, the authors describe the use of instructor-patients to teach and evaluate physical examination techniques. The main emphasis is on the recruitment, training and performance of these non-physician instructors. It is concluded that the introduction of lay instructors in any phase of the teaching of physical diagnosis leads to great precision in identifying what has to be learned, what are the optimum techniques and what constitutes an acceptable performance.