The COVID-19 is a global crisis that has brought about a ton of negative consequences. Especially, fearfulness more or less arose in everyone during the pandemic and had bad impacts on their daily life. Furthermore, finding out the predictors of their fear is necessary to come up with strategies to lower the fear. All of that makes examining their fear of COVID-19 more necessary than ever. This study examined Vietnamese undergraduates' fear of COVID-19 and found out some predictors of their fear. Our cross-sectional study was conducted on Vietnamese students using The Fear of COVID-19 Scale. To determine if demographic variables are a predictor of fear of COVID-19 among undergraduate students. Pearson’s correlation and linear regression analysis were conducted. The data were analyzed by the Statistical Package for the Social Sciences (SPSS) version 20.0 with considering a significant p-value ≤ of 0.05. The results indicated that: (1) students in Vietnam suffered from a medium level of fearfulness (M = 21.66, SD = 5.83); (2) females had a serious fear of COVID-19 in comparison with males; and (3) the students’ gender, university, school year, their number of Family size and their moving status significantly predicted their level of fear for COVID-19. In conclusion, the student's gender, university, school year, their number of Family size, and moving status were significant predictors for their fear of COVID-19.