A case of complex regional pain syndrome (CRPS) secondary to peripheral nerve injury occurring during venipuncture for post-contrast CT examination is presented. The puncture site was in the left antecubital fossa. Anatomically, cutaneous nerves lie close to cutaneous veins, making them vulnerable to injury during the procedure. This syndrome is characterized by continuing pain, allodynia, or hyperalgesia that is disproportionate to any inciting event in severity, and may lead to loss of the involved limb. The syndrome is poorly understood by radiologists and is often misdiagnosed. Early recognition and appropriate therapy are most important in treating this disorder.