A prospective study of 100 post-evacuation barium enemas was done. Films were centered at McBurney's point, with an opaque skin marker at that point. Analysis of these revealed that in only one case (1%) was the base of the appendix at McBurney's point. In 67% it was cephalic and in 32% it was caudal to this point. The limitations of McBurney's point as an anatomical landmark should be recognized. This needs to be highlighted in teaching anatomy, especially to surgical trainees. Planning and choice of surgical incisions should be based on an understanding of these anatomical variations since McBurney's original description was clinical rather than anatomical.