There are few reported cases of flexor pollicis longus tendon (FPL) rupture complicating a closed distal radius fracture. We report a case of FPL tendon rupture complicating a closed distal radius fracture. A 24-year-old male presented with a severe right wrist pain. He had a closed distal radius fracture that was treated by closed manual reduction. Three days later, he complained forearm pain and limitation of thumb motion. The physical examination revealed loss of active interphalangeal joint flexion of thumb. He was taken to the operating room. Intraoperatively, the FPL was found to be discontinuous at the level of the radius fracture site. The FPL was repaired by a modified Kessler technique, and the fracture was repaired with a volar plate. Clinicians must be cautious in possibility of tendon injury complicating a closed distal radius fracture and assessing patients with distal radius fracture following closed reduction.