Overview Introduction The anterolateral thigh (ALT) flap allows for healthy, reliable, vascularized, soft-tissue coverage of extremity or axial defects of traumatic or acquired deformities. Indications & Contraindications Step 1: Positioning and Markings Place the patient in the supine position, which allows for flap harvest and typically does not require any position changes (Fig. 1), and then mark the septum between the vastus lateralis and rectus femoris, which facilitates harvest of this flap (Video 1). Step 2: Perforator Dissection Dissect this flap, which is relatively straightforward and rapid after identifying the perforating vessels (Video 2, Fig. 4). Step 3: Pedicle Dissection Trace the course of the descending branch of the lateral femoral circumflex proximally and determine the maximum pedicle length and vessel diameter for microvascular anastomoses (Figs. 5 and 6). Step 4: Flap Harvest and Recipient Vessels Confirm the dimensions of the flap prior to final harvest of the flap, and pay special attention to the recipient arterial inflow and venous outflow to ensure success . Step 5: Microvascular Anastomoses When performing this flap as a microvascular free flap, identify and prepare suitable vessels for tissue transfer (Fig. 13). Step 6: Flap Inset Pay special attention to the flap inset to ensure that there is no mechanical obstruction to the pedicle and that the inset allows for the anticipated postoperative edema (Figs. 14 and 15). Step 7: Donor Site Closure Close the donor site for this flap, which is well tolerated and easily concealed (Fig. 16). Step 8: Flap Monitoring and Postoperative Care Postoperative monitoring is critical to identify any potential vascular compromise early and maximize successful outcomes 4 . Results The ALT is a highly successful and reliable flap that has become a workhorse of reconstructive microsurgery 5 . Pitfalls & Challenges