BackgroundInsufficient arterial blood flow is the one cause of flap necrosis. Cilostazol is an inhibitor of phosphodiesterase III and increases cyclic AMP level in vascular smooth muscle cell causing vasodilation. Therefore, effect of cilostazol is expected to improve the viability of the flap.MethodsDouble blinded randomized controlled trial was conducted. The study was to compare the survival of dorsal rat flaps between preoperative cilostazol supplemented diet and regular diet. The flap survival area was measured using PixArea Image software on post operative day 1,3,5 and 7. Fluorescein injection was performed to evaluate the exactly area of flap survival on postoperative day 7 and morphology of arterioles and venules were examined by histopathologic examination.ResultsA statistical significance was found in the percentage of area of flap survival between cilostazol supplemented diet and control group on postoperative day 3, 5 and 7 (p < 0.05). Fluorescein injection showed the higher area of flap survival in cilostazol group than the control group (p < 0.05). Histopathologic examination showed dilation of vessels in the cilostazol group.ConclusionPreoperative cilostazol in rats can enhance skin flap survival.Electronic supplementary materialThe online version of this article (doi:10.1186/s13022-015-0011-4) contains supplementary material, which is available to authorized users.