Objectives; Yellow fever, viral hemorrhagic fever transmitted by mosquito, is one of the most lethal disease. A live attenuated yellow fever vaccination(YFV) is required to all people who visit yellow fever endemic countries. The information of the risk of adverse events is lacking in Korea, especially overseas dispatch soldiers. Therefore, we carried out this study to provide information about YFV. Methods; This study was performed at the clinic on board Munmu the great from February 7 to February 8, 2018, for evaluating the adverse events of YFV. 221 healthy adults were vaccinated YFV and were prospectively monitored for adverse events through close observation in warship and questionnaire. Results; Local adverse events were observed in 10(4.5%) and systemic adverse events were observed in 65(29.4%). The common adverse events were chilling sense in 35(15.8%), headache in 33(14.9%). The patients with fever above 38.3℃ were admitted and were prescribed oseltamivir according to cough. There was no difference of hospital day according to oseltamivir(p=0.834). Conclusions; Results of this study showed adverse events by YFV. Most adverse events were mild and were treated in warship. Severe adverse events can happen in 2 weeks after vaccination, so vaccination should be performed at least 2 weeks before departure.