The mental health of high school students in Vietnam is facing numerous challenges due to academic pressure, important examinations, societal expectations, and the impact of the digital environment. In this context, the application of digital technology, especially personalized mental health apps, is considered a potential solution to help students manage stress, enhance concentration, and improve their quality of life. This study aims to analyze the factors (i) “Perceived Need for Mental Health Care”, (ii) “Perceived Usefulness”, (iii) “Perceived Ease of Use”, and (iv) “Subjective Norm” influencing high school students' intention to use personalized mental health apps. The results indicate that Perceived Usefulness (PU) and Subjective Norm (SN) significantly influence BI, with PU being the strongest influencing factor. This implies that students are only willing to use the apps if they clearly perceive practical benefits and receive encouragement from family, friends, and school. The research findings contribute empirical evidence to the applicability of TPB and TAM in the context of school mental health in Vietnam.