AbstractPurpose Despite concerns about the attrition of the post‐operative endothelial cell density (ECD), endothelial keratoplasty, whatever the method of lenticule preparation has gain popularity over penetrating keratoplasty because of a short/medium‐term favourable benefit/risk balance. Because the long and very long‐term issues may mostly depend on the endothelial cell (EC) pool brought by the graft, and because the supplementary handling necessary to cut the lenticules may stress EC, we focused our attention on the EC viability of endothelial lenticulesMethods Systematic review of the literature and experimental data from our laboratoryResults We indentified in PubMed, articles where EC viability was assessed after lenticule preparation, and those with post‐operative clinical data. Methods of EC assessment and interpretation were analysed. Experimental assessment using a specifically designed triple Hoechst/Ethidium/Calcein staining coupled with image analysis of the whole graft surface provide a precise objective determination of the viable ECD (vECD), the only which is important for the recipient.Conclusion Almost all published series show that the preparation of endothelial lenticules trigger a significant EC loss. Reduction of initial ECD is liable to have long or very long‐term functional consequences, that remain to be investigate (maximal published follow‐up is only of 4‐5 years). Experimental data, especially the vECD, allow a precise quantification of the phenomenon and therefore comparison between different cutting techniques. There are strong bodies of evidence proving that we don’t graft as many EC as we think