Purpose: To compare the obliquity of femoral tunnels prepared with transtibial (TT) versus anteromedial portal technique (AM) using x-ray in single-bundle anterior cruciate ligament (ACL) reconstruction. Materials and Methods: Among one-hundred thirty two patients who were undergoing ACL reconstruction from January 2007 to December 2009, thirty patients using TT and twenty patients using AM, those who had single-bundle ACL reconstruction, were evaluated with plain radiographs including anteroposterior, intercondylar notch and lateral view to compare the obliquity of bone tunnels. Results: The mean coronal obliquity of femoral tunnel for TT was $71^{circ}$ (range; $65^{circ}{sim}77^{circ}$), while for AM was $51^{circ}$ (range; $39^{circ}{sim}60^{circ}$) and the mean sagittal obliquity of femoral tunnel for TT was $22.7^{circ}{pm}7.8$, while for AM was $30.2^{circ}{pm}6.9$, their differences between them were statistically significant (P<0.05). However, there were no differences between two techniques on the tibial tunnel obliquity in coronal and sagittal plane. Conclusion: Anterior cruciate ligament reconstruction using AM portal technique allows more horizontally oriented and divergent femoral tunnel compared to that of transtibial technique. This seems to enable the graft placement into the femoral footprint and preserve the posterior cortical wall.