Compartment syndrome is a rare complication after anterior cruciate ligament (ACL) reconstruction. This is one of the most devastating complications after surgery of the lower limb, with certain risks of renal failure, shock, and even death. We report a case of compartment syndrome that occurred 12 h after ACL reconstruction. A healthy 67-year-old male who underwent transtibial ACL reconstruction using autogenous hamstring tendon graft complained of progressive intense pain, paresthesia, and paresis. He had a pallid aspect and taut, shiny skin with several blisters around the medial aspect of the lower limb. Computed tomography revealed a hematoma that originated from the tibial bone tunnel. The patient was immediately referred for an urgent decompression fasciotomy. Hematoma debridement, medial fasciotomy, and negative-pressure wound therapy were performed. The patient recovered well and received routine postoperative physiotherapy.