Complex regional pain syndrome type I (CRPS I) is a disorder of one or more extremities characterized by pain, abnormal sensitivity (allodynia), swelling, limited range of motion, vasomotor instability, fatigue and emotional distress. The symptoms may be aggravated by even minor activity or weather change. It is usually provoked by injury, surgery or injection but in a small proportion of patients CRPS I develops without a clear causative event. There are several literature reports on CRPS after rubella and hepatitis B vaccination. We present a case of CRPS I affecting the left arm after diphtheria and tetanus (Di-Te) vaccination in the left deltoid muscle in a young girl having experienced profound emotional stress before the vaccination procedure. History data on previous minor trauma at the site of vaccination or emotional stress may necessitate temporary vaccination delay due to their proneness to impaired local or systemic immune response and CRPS as a complication of vaccination. If a child or an adult has prominent swelling and severe pain after vaccination, the diagnosis of CRPS I should be considered and if confirmed, the multidisciplinary treatment should start as soon as possible.