This paper is conducted to scrutinize the effect of the COVID-19 pandemic on the mental health of Vietnamese university students who are living and studying in the US. Specifically, the objective of this research is to survey the severity and the different grounds of mental distress among this population group throughout the awful pandemic. The result collected from the online questionnaire survey revealed that among 103 participants, 79.61% (n=76) experienced a mild-to-severe level of mental distress. This mental health issue is attributed to the increasing stressors related to studying, health, and general living triggered by the complicated COVID-19 outbreak situation.