A new method for evaluating the circulation in surgical flaps using laser-induced fluorescence of indocyanine green (ICG) images is reported. In clinical trials the authors found that ICG imaging demonstrated good circulation accurately in 16 of 21 flaps with no clinical manifestations of compromised circulation. In 3 patients in whom partial discoloration and cyanosis of the flaps were visible, the dye study indicated poor circulation in the identical areas. In 2 other patients in whom flaps appeared clinically satisfactory, the flaps were shown by ICG imaging to have greatly compromised circulation. In a patient in whom the flap was left in place, slough of almost the entire flap resulted. Another flap with questionable circulation was returned to its original location, where it healed. Thus, while it is a still a new approach and under continual evaluation, the use of ICG fluorescence shows promise as a valuable adjunct to current methods of flap evaluation.