Total knee arthroplasty (TKA) is an effective treatment for patients with end-stage symptomatic knee osteoarthritis. As the aging population grows, the demand for the procedure is projected to increase. While highly successful, TKA has associated risks and complications. Complex regional pain syndrome is one uncommon but debilitating complication that can negatively impact patient satisfaction and quality of life. We present a case of complex regional pain syndrome in the operated leg that resulted in significant functional deficits. Key findings of this case include significant and disproportionate pain in the joint, altered cutaneous sensation around the joint, and decreased range of motion in flexion in the absence of any mechanical issues with the TKA. Because of the debilitating nature of this condition, patients must be fully informed of and realize the risks associated with undergoing a widely appreciated procedure such as TKA.