The Radiologic Learning File is a means of radiologic self-instruction for residents and is a training aid to clinical medicine and radiology for undergraduates. Approximately 1,200 clinically and pathologically documented roentgenographic cases ideally arranged for efficient learning illustrate practical diagnostic problems. Normal and abnormal studies are constantly compared, and varied disorders with similar roentgen manifestations are examined consecutively to highlight distinguishing features. As a supplement to early clinical training, the Learning File experience should increase learning efficiency comparable to that resulting from exposure to a random flow of patients.