Background: The current method of analyzing myocardial cell transplanation relies on postmortem histology. We sought to demonstrate the feasibility of monitoring transplanted cell survival in living animals using optical imaging techniques. Methods: Umblical cord blood was collrected upon delivery with informed consent. Umblical mononuclear cells were obtained by negative immuno-depletion of CD3, CD14, CD19, CD38, CD66b, and glycophorin-A positive cells, followed by Ficoll-Paque density gradient centrifugation, and plated in non-coated tissue culture flasks in expansion medium. Cells were allowed to adhere overnight and non-adherent cells were washed out with medium changes. After getting the MSCs, they were transfected [multiplicity of infection (MOI) = 40) with Ad-CMV-Fluc overnight. Rats (n=4) underwent intramyocardial injection of 5 x 10⁵ MSCs expressing firefly luciferase (Fluc) reporter gene. Optical bioluminescence imaging was performed using the charged-coupled device camera (Xenogen). Results: Cardiac bioluminescence signals were present from 2nd day of transplantation. Cardiac signals were clearly present at day 2 (9.2 x 10³ p/s/cm²/sr). The signal reduced from day 3. Conclusion: The locations, magnitude, and survival duration of cord blood derived MSCs were monitored noninvasively. With further development, molecular imaging studies should add critical insights into cardiac cell transplantation.