Anatomic rectangular tunnel anterior cruciate ligament (ACL) reconstruction, which has been reported by Shino and colleagues, can mimic the natural arrangement of the native ACL fibers using a bone-patellar tendon-bone graft. We modified their technique into a transtibial procedure resulting in several advantages. It is easy to identify the femoral attachment from the anteromedial portal and create the femoral tunnel without deep knee flexion. Therefore, it eliminates potential pitfalls, such as malpositioning of the femoral tunnel and posterior femoral cortex blowout. Furthermore, introduction of the bone-patellar tendon-bone graft into the femoral tunnel is easier than the transportal technique. This technique will be familiar for surgeons who have performed the conventional transtibial technique and can easily reproduce an anatomic ACL.