Strongyloides hyperinfection and dissemination are recognized complications in kidney allograft recipients; however, the development of strongyloidiasis in renal transplant recipients receiving cyclosporine A (CyA) has not been described, nor has the development of strongyloidiasis in other organ transplant recipients. The former observation has been attributed to the antiparasitic activity of CyA seen in animal studies; the latter has no explanation yet. We report the first case of Strongyloides hyperinfection in a renal transplant patient occurring immediately after CyA was discontinued. From the unique characteristics of this case, it appears that the anti-Strongyloides activity of CyA in animals may also be found in humans.