Five hundred and thirty-two patients underwent microsurgical reconstruction following trauma to their extremities. They were divided into three groups for the purpose of review. Group 1 underwent free-flap transfer within 72 hours of the injury, group 2 between 72 hours and 3 months of the injury, and group 3 between 3 months and 12.6 years, with a mean of 3.4 years. The results were analyzed with respect to flap failure, infection, bone-healing time, length of hospital stay, and number of operative procedures. The flap failure rate was 0.75 percent in group 1, 12 percent in group 2, and 9.5 percent in group 3 (p less than 0.0005 early versus delayed; p less than 0.0025 early versus late). Postoperative infection occurred in 1.5 percent of group 1, 17.5 percent of group 2, and 6 percent of group 3. Bone-healing time was 6.8 months in group 1, 12.3 months in group 2, and 29 months in group 3. The average length of total hospital stay was 27 days for group 1, 130 days for group 2, and 256 days for group 3. The number of operations averaged 1.3 for group 1, 4.1 for group 2, and 7.8 for group 3.