Background: Anterior Cruciate Ligament (ACL) injury is the most common knee ligament injury. The existence of an ACL injury affects functional status. Management of ACL injury with operative therapy ie ACL reconstruction with arthroscopy or non operative therapy ie medical rehabilitation depends on knee condition and patient needs. This study was conducted to determine how much the effect of ACL injury management mentioned on the functional status of the patients. Methods: Descriptive case control analytical study was conducted on 32 patients with ACL injury in the period of 2015-2017 at RS Panti Rapih and RS JIH. The subjects were divided into 2 groups: 16 subjects undergone operative therapy and 16 subjects undergone non operative therapy. Functional status measurements were performed before therapy and 3 months after therapy with Knee Injury and Osteoarthritis Outcome Score (KOOS) questionnaire. Result: The analysis with paired t test in the operative group obtained P value 0.002 and in the non operative group obtained P value 0,000. Analysis with independent t test showed that the average of functional status 3 months after treatment was 80,50 ± 16,62 in operative therapy and 76,75 ± 13,48 in non operative therapy with P value 0,489. Conclusion: Operative and nonoperative therapy performed consistently in ACL injury patients provides significantly improved functional status than before therapy. There were no significant differences on functional status between operative and non operative therapy at 3 months follow up.