Based on a study of true lateral roentgenograms of the proximal ends of fifty normal tibiae, and on roentgenographic and direct measurements of anatomical specimens with experimentally depressed plateaus, it was demonstrated that the plane of the proximal articular surfaces of the tibia normally forms an angle of 76 ± 3.6 degrees with the tibial crest, and that an anteroposterior view made with the central ray directed at an angle of 105 degrees to the tibial crest (the approximate complement of the aforementioned 76-degree angle) permits the most accurate roentgenographic measurement of the depression. It was concluded that use of the "tibial-plateau view" permits more accurate assessment of the initial depression and the effects of treatment.