Background: Tunnel expansion in anterior cruciate ligament reconstruction (ACL-R) is a well-accepted phenomenon, still its effect on functional outcome is little known. Purpose: To study prospectively the effect of change in the tunnel volume as observed with computed tomography (CT) on functional outcome after ACL-R. Materials and Methods: This study conducted for a follow up of 24 months of time period between June 26th 2017 to 31st December of 2019, after approval from ethical committee 31 patients with complete ACL tear with or without the meniscal injury were treated with single bundle arthroscopic reconstruction using hamstring tendon graft. With common postoperative rehabilitation protocol, all patients were followed up clinically and radiologically for two years. Tibial and femoral tunnel volume were measured and correlated with the clinical parameters. Radiological parameters were summarized as mean, standard deviation and proportions as applicable.