Initial information received on 23-Nov-2018 regarding an unsolicited valid serious case issued from a literature article. Introduction: Few cases of acute allergic reaction to Yellow Fever Vaccine (YFV) are reported. We present a case of delayed urticarial and angioedema (U&A) following YFV immunization. Discussion: We suspect that our patient developed delayed non IgE mediated reaction YFV. Healthcare providers should take caution administering YFV to patients with an underlying malignancy. A complete medical history is needed to determine risk benefit ratio of YFV immunization. This case involves a 51 years old female patient who experienced progressive neurological symptoms over a period of time, had hypertension, and developed episodic Urticaria and Angioedema responsive to steroids, while she received vaccine YELLOW FEVER VACCINE. The patient's past medical history include multiple medical problems including history of malignancy. The patient's past medical treatment(s), vaccination(s) and family history were not provided. On an unknown date, the patient received a dose of suspect YELLOW FEVER VACCINE produced by unknown manufacturer, lot number not reported via unknown route. On an unknown date, the patient developed a serious progressive neurological symptoms over a period of time (nervous system disorder) two days following the administration of YELLOW FEVER VACCINE. The patient was hospitalized for this event. It was also reported that patient was treated symptomatically and discharged on an unknown date. On an unknown date, the patient developed a serious hypertension (hypertension) following the administration of YELLOW FEVER VACCINE. The patient was hospitalized for this event. It was also reported that but extensive laboratory and radiology evaluations were not contributory. On an unknown date, the patient developed a serious episodic Urticaria and Angioedema responsive to steroids, delayed urticarial (Urticarial and Angioedema) three weeks following the administration of YELLOW FEVER VACCINE. The patient was hospitalized for this event. (Other relevant tests included she had elevated CRP and ESR.) Final diagnosis was developed episodic Urticaria and angioedema responsive to steroids, hypertension and progressive neurological symptoms over a period of time. An unknown corrective treatment was received. The patient outcome is reported, as Recovered / Resolved on an unknown date for she developed episodic Urticaria and Angioedema responsive to steroids, as recovering for progressive neurological symptoms over a period of time (mentioned as improved) and as Unknown for hypertension. It was reported that at two month follow up Urticaria and Angioedema symptoms completely resolved. Reintroduction of medications did not cause Urticaria and Angioedema. List of documents held by sender- none. Sender's Comments: This case concerns a 54 years old patient  who experienced Urticaria and Angioedema three weeks and Neurological disorder after two days and hypertension after vaccination with Yellow fever vaccine produced by unknown manufacturer. Time to onset is compatible with the role of vaccine. However, further information including patient's medical history, condition at the time of vaccination, vaccine details, laboratory investigations excluding other etiology would be needed to fully assess this case. Based on available information the role of vaccine cannot be assessed.