Five pairs of rabbit corneas were stored for two weeks at 4 degrees C, one of each pair in K-Sol medium, and one in McCarey-/Kaufman (M-K) medium. After transplantation all penetrating keratoplasty grafts became clear and thin. Endothelial cell loss was significantly less in the K-Sol stored corneas. Another five pairs of corneas were stored for two weeks in K-Sol or three days in M-K medium. After penetrating keratoplasty there were no significant differences in clarity, thickness, or endothelial cell loss. The results indicate that K-Sol provides satisfactory medium-term corneal storage compared with short-term storage in M-K medium at refrigerator temperatures.