Mental health literacy (MHL) is essential for high school students to promote the quality of their mental health as well as help people in need. In Vietnam, studies about MHL in high school students are limited, and results often report a moderate level of MHL. The aim of this study was to report the MHL status of high school students in Ho Chi Minh City. Participants were 577 students selected from several high schools in Ho Chi Minh City and then were assessed using the Mental Health Literacy Scale (28 items) which has been validated into Vietnamese for better adaptation to high school Vietnamese students. The mean score of MHL in the research was 77.47, representing the moderate level. Meanwhile, the proportion of students with moderate levels accounted for 63.60%, followed by the high ones at 31.37% and the remaining was for the low level, at 5.03%. Therefore, MHL is of paramount importance to be conducted further research for laying a foundation for providing feasible solutions to improve MHL particularly and mental health quality generally of high school students.