Increased tibial slope can be a cause of recurrent instability after anterior cruciate ligament reconstruction. This article presents a technique for an anterior closing-wedge osteotomy for slope correction. The indications for this procedure are patients with recurrent instability after anterior cruciate ligament reconstruction with a neutral leg axis or slightly varus deformity and a posterior slope of more than 12°. The exposure of the anterior aspect of the tibia is best made through an anterior approach approximately 1 to 2 cm medial to the tibial tuberosity. Hohmann retractors are placed from the medial and lateral sides behind the proximal tibia. The osteotomy lines are marked with 2 converging Kirschner wires with the use of an image intensifier. The entry point of the first Kirschner wire is just below the most inferior fibers of the patellar tendon. The hinge of the osteotomy should be just below the tibial insertion of the posterior cruciate ligament. The osteotomy is performed with an oscillating saw. The posterior cortex of the tibia should be left intact. After removal of the anterior base wedge, the osteotomy is closed by manual pressure. Osteosynthesis is performed with a lag screw from the tibial tuberosity to the distal tibia and an angular stable plate fixator.