Anterior cruciate ligament (ACL) is the most commonly injured ligament occurs in young adult population, which markedly reduces activity level. Anterior cruciate ligament rupture is a threat to the homeostasis of the knee. So, reconstruction of the ACL is necessary to make them fit and return to their pre-injury activity level. The choice of graft for ACL reconstruction is a matter of debate, with the BPTB graft and quadruple graft of ST-G being the two most popular options. Use of triplet graft of semi-tendinosus tendon alone without sacrificing gracilis is another option. So hypothesis was Arthroscopic ACL reconstruction with triplet autograft of semi-tendinosus tendon alone is an effective procedure. This prospective interventional study was conducted from October 2011 to March 2013 at Dhaka Medical College Hospital, Dhaka, Bangladesh. Fourteen patients who had a unilateral anterior cruciate ligament rupture underwent arthroscopic reconstruction with triplet graft of semi-tendinosus tendon. Accelerated ACL reconstruction rehabilitation protocol was followed and final outcome evaluation done at 24 weeks according to IKDC knee examination form and Lysholm knee scoring scale. Preoperative Lysholm knee score was 52.64 and postoperative score was 90, that shows significant improvement (p<0.05). According to Lysholm knee scoring scale, excellent results (95-100 points) were obtained in 33% patients, good results (85-94 points) in 53% patients, fair and poor (7% each). For arthroscopic ACL reconstruction, choice of semi-tendinosus tendon alone preserving gracilis, comparable outcome as with BPTB/ST-G graft, can be achieved, minimizing the hamstring strength deficit. Moreover gracilis being reserved for future use in revision ACL reconstruction and/or in other reconstructive surgery.