The corneal endothelium in nine cases of keratoconus (18 eyes) was analyzed quantitatively for mean cell area and standard deviation (SD) of cell area to determine the presence of polymegathism. Four of the subjects were veteran wearers of rigid contact lenses and five of the subjects had not worn contact lenses previously. The subjects were matched for age, sex, and contact lens history with a group of normals. The endothelium in eyes with keratoconus did not show a significant increase in the extent of polymegathism as compared with controls. There was no significant difference in mean cell area between the study group and the control group. These results suggest that polymegathism in keratoconic patients may be related to contact lens wear. © 1987 American Academy of Optometry.