Gait mechanics alternation remain after anterior cruciate ligament reconstruction (ACLR). Evaluating the center of pressure (COP) trajectory is one of the variables that reflects whole mechanics of walking and running. The aim of this study was to compare the COP trajectory in people with a history of ACLR surgery. 48 male basketball players (24 with history of surgery and 24 healthy) participated in this study. The barefoot walking and running COP of both legs of the subjects was recorded by the footscan device in two medio-lateral and antero-posterior directions and was calculated in 4 subphases of the stance phase. The results showed that COP trajectory in walking and running was more medially directed in the forefoot push-off subphase in the ACLR group. Also, in the ACLR group, COP of the injured leg in the forefoot push-off subphase during walking and running was more medially directed than the healthy leg. Regarding the results of the present study, it can be concluded that the COP trajectory is different from that of healthy subjects after ACLR. This difference in COP trajectory can result in altered knee loading and increase risk of knee osteoarthritis.