No definitive etiology or risk factors have been identified that predispose individuals to developing complex regional pain syndrome (CRPS). We experienced two cases of CRPS developed after arterial and venous puncture which were done in regular medical work. A 35-years old female patient was suffered from pain and allodynia with swelling at right hand and wrist after radial artery puncture for monitoring of blood pressure during general anesthesia. A 24-years old male patient had pain and swelling with allodynia at the right fingers and arm after median cubital vein puncture for blood sampling. They did not have proper pain management as CRPS patients in the past weeks and months after their pain occurred. They were diagnosed as CRPS and started undergoing various interventional procedures, which led to improve their pain condition. Our cases suggest that CRPS could develop without any proved tissue damage in routine medical practice. In conclusion, health care workers should be educated in knowledge about the uncommon medical condition and proper consultation to pain specialist when it happens.