One hundred clear corneal grafts with a minimum follow-up of 10 years and average follow-up of 17.4 years were studied with specular microscopy. Central and peripheral graft endothelial cell counts as well as central corneal thickness measurements were done and these were correlated with the following parameters: diagnostic subgroups; donor age; graft age (follow-up time); and the postoperative clinical course. The average central endothelial cell counts for the entire series was 684 cells/mm2. Peripheral cell counts were performed in 78 eyes and averaged 749 cells/mm2. Central corneal thickness was measured in 80 eyes and averaged 0.49 mm. There were no statistically significant differences in central or peripheral cell counts when analyzing donor age, graft age, or postoperative course. When cell counts were examined among the diagnostic subgroups, those in the hereditary stromal dystrophy subgroup had a significantly lower cell density when compared to those in the keratoconus subgroup.