As the vaccination efforts against the coronavirus disease‐2019 (COVID‐19) continue, more patients are likely to present with complications related to COVID‐19 vaccination. We describe the first reported case of complex regional pain syndrome (CRPS), involving the upper extremities, that occurred after COVID‐19 vaccination. The patient presented with acute‐onset severe arm pain and swelling following vaccine administration. Based on the clinical, electrodiagnostic, and radionuclide three‐phase bone scan findings, the patient was diagnosed with postvaccination CRPS. The COVID‐19 vaccine possibly elicited an immune‐mediated inflammatory response to the injected antigen in the patient, who was predisposed to CRPS due to inflammatory immunity. The COVID‐19 vaccine elicited an immune‐mediated inflammatory response to the injected antigen, resulting in CRPS following COVID‐19 vaccination.