The no-reflow phenomenon is one of the factors that increase morbidity in flap and replantation surgery. Prevention and treatment of the phenomenon is an area of intense current research. This study investigated the possible effect of cyclosporin administered systemically on survival of skin flaps subjected to ischaemia-reperfusion injury. Cyclosporin treated flaps showed a statistically significant increase in survival areas regardless of the time of infusion (p < 0.01). These findings suggest that cyclosporin could be valuable in preventing or treating no-reflow in critical flaps. Possible mechanisms of action are discussed.