We performed arthroscopic anterior cruciate ligament (ACL) reconstructions of chronic ACL rupture with autologous hamstring tendon grafts in males (mean age 23.9 years). Thirty-two cross-pin fixations and 24 EndoButton CL fixations were performed on the femoral side. Distal fixations on the tibial side were maintained with interference screws plus a staple. Tunnel enlargement was evaluated using X-rays. Femoral and tibial tunnels were measured at three levels 5 mm apart, and average enlargement was calculated after correction for magnification. Tunnel enlargement 12 months after surgery was greater for the EndoButton CL system (femoral side 43.71%, tibial side 51.11%) than for the cross-pin system (femoral side 32.61%, tibial side 25.62%); the difference was significant only on the tibial side. Both proximal fixation techniques were judged clinically successful (follow-up 16 - 36 months). The far fixation point in the EndoButton CL group may be related to mechanical loosening.