University students are increasingly affected by mental health problems and need prompt support. The aim of this project was to assess the impact of the mental health first aid (MHFA) training on students' knowledge, attitudes and practices (KAP) concerning mental health in the short, mid and long-term. Three studies were conducted in Bordeaux, France, from May 2021 to March 2022. The first study collected data from 55 students 1 to 6 months after they had followed the training to examine its efficacy in the mid-long term. The second study collected data immediately before and after the training to evaluate the KAP of 52 students in the short-term (1 to 10 days). The third study consisted of 14 semi-structured interviews with students trained since 2020 to identify the training's long-term impact (3 to 18 months). Descriptive statistics were used for studies one and two, and framework analyses for study three. Most participants reported that their KAP about mental health had improved after the training. In the first study, 94.2% of students reported being ready to intervene during a psychotic crisis in their peers. In the second study, 75.0% of students reported improved mental health-related knowledge and decreased stigma. All students in the third study reported that they had assisted at least one person after the training. These were the first data on the impact of the French MHFA on KAP. While not exhaustive, findings suggest that deploying the training would be beneficial to French students.