Anterior Cruciate Ligament Reconstruction and Effect On Tibial Rotation Restoration of rotational kinematics after reconstruction of anterior cruciate ligament, has been difficult to obtain and to quantify at the time of surgery. The purpose of this study was to determine whether position on the femoral tunnel, can restore rotational kinematics in knees in which semitendinous – gracillis has been used to reconstruct the ligament. Femoral graft positioning will affect knee kinematics. Prospective, randomized clinical trial. Fifty-nine male patients undergoing semitendinous – gracillis autograft anterior cruciate ligament reconstruction using 2.0 Ortho Pilot navigation system- by a single surgeon were randomized in two groups: Group 1, femoral tunnel between ten-nine, two-three o'clock (N= 28) and Group 2, femoral tunnel at eleven – one o'clock (N= 31); none of them had other ligament involved. Anterior displacement and internal (IR) and external (ER) rotation at 30° of flexion were evaluated before and after reconstruction, using manual maximum force. Both groups significantly reduce anterior displacement and rotation of the tibia with respect to previous ligament condition (p <1). If we compare groups, there were no differences in anterior translation (Group 1: 2.8 mm, Group 2: 3.4 mm) (p=.06). In relation to internal and external rotation, differences were found (Group 1: IR 10.2 °, ER 9.4° Group 2: IR 16.6°, ER 14.8°), (p=0.02). The hypothesis that femoral graft positioning affect rotational stability is confirm.