Purpose.To report the early clinical results of the first U.S. patients to undergo deep lamellar endothelial keratoplasty (DLEK) surgery for the treatment of endothelial dysfunction.Methods.Two patients with pseudophakia with Fuchs' endothelial dystrophy, under an Institutional Review Board-approved protocol, underwent replacement of the endothelium through a limbal, scleral pocket incision (DLEK). Their vision, pachymetry, and corneal map topography were measured in the early postoperative period and were compared with preoperative measurements.Results.Both patients had improvement in all parameters within 1 month after surgery, and corneal topography showed no significant change from before the surgery. The first patient's vision at 6 months was 20/40 (+2) with a 0.75-diopter (D) decrease in astigmatism and a normal pachymetry of 573 &mgr;m. The second patient's vision at 6 months was 20/40 (−2) with a 0.25-D increase in astigmatism and a pachymetry of 618 &mgr;m. Graft endothelial cell counts at 6 months were 1,692 and 2,631 cells/mm2, respectively.Conclusion.The DLEK procedure, with its absence of corneal surface incisions and sutures, preserves the preoperative topography and demonstrates good donor endothelial cell count and function early in the postoperative period. If interface clarity can be maintained, the potential advantages over penetrating keratoplasty in the treatment of endothelial dysfunction are considerable.