A few days ago I committed a patch with which I tried to improve the coordinate handling of annotation. And I updated the annotation guide which describes the change in some detail. http://matplotlib.sourceforge.net/trunk-docs/users/annotations_guide.html#using-complex-coordinate-with-annotation And here is an example http://matplotlib.sourceforge.net/trunk-docs/examples/pylab_examples/annotation_demo3.html I hope this is useful for others as this has been one of my wishlist. Regards, -JJ