Viability of human corneas stored in moist chambers was evaluated by histochemical staining of endothelium for lactic dehydrogenases and oxygen consumption by corneal stroma. The period between death and enucleation was taken into account to compute the total storage time which extended up to 264 hours. The study was done in pairs of eyes with normal biomicroscopic appearance at time of enucleation. With increased storage time permeability of endothelial cells to nitro-blue tetrazolium (NBT) stain increased in a greater number of cells. The respiratory quotient (QO2) of corneal stroma decreased with storage time and was indicative of stromal cell alteration or death.