Complex regional pain syndrome (CRPS) is a disease with unclear pathophysiology. The condition is characterized by pain, soft tissue change, vasomotor change, and even psychosocial disturbance. It may affect the upper more than the lower extremities, and the distal more than the proximal. The trigger factors include carpal tunnel release, Dupuytren's repair, tendon release procedures, knee surgery, crush injury, ankle arthrodesis, amputation, and hip arthroplasty. Rarely, it has been associated with stroke, mastectomy, pregnancy, and osteogenesis imperfecta. Herein, we present a rare case of a patient who was diagnosed with CRPS after transradial cardiac catheterization. CRPS was first diagnosed due to hand swelling, allodynia, paresthesia, and the limited range of motion of interphalangeal, metacarpophalangeal, and wrist joints, with the preceding factor of transradial cardiac catheterization, and was then confirmed by a three-phase bone scan. After intensive physical therapy with hydrotherapy, manual soft tissue release, and occupational therapy for the hand function, there was much improvement in range of motion and hand function. There was no allodynia or painful sensation in the follow-up. After training, the functional status of this patient was adequate for daily activity.