Background: There is a rapidly growing public awareness of mental health problems among Vietnamese secondary school students. This study aims to determine the prevalence of anxiety, depression, and suicidal ideation, to identify related risk factors, and to explore students' own proposals for improving their mental health. Methods. A cross-sectional study was conducted among 1161 secondary students in Can Tho City, Vietnam during September through December, 2011. A structured questionnaire was used to assess anxiety, depression, suicidal ideation and proposed solutions. Depression was measured using the Center for Epidemiology Studies Depression Scale. Results: The prevalence estimates of symptoms reaching a threshold comparable to a diagnosis of anxiety and depression were 22.8% and 41.1%, respectively. Suicide had been seriously considered by 26.3% of the students, while 12.9% had made a suicide plan and 3.8% had attempted suicide. Major risk factors related to anxiety and depression were physical or emotional abuse by the family, and high educational stress. As proposed solutions, nearly 80% of students suggested that the academic workload should be reduced and that confidential counselors should be appointed at schools. About half the students stated that the attitudes of their parents and teachers needed to change. A significant majority said that they would visit a website that provided mental health support for students. Conclusions: Anxiety, depression, and suicidal ideation are common among Vietnamese secondary school students. There are strong associations with physical and emotional abuse in the family and high educational stress. Academic curricula and attitudes of parents and teachers need to be changed from a punitive to a more supportive approach to reduce the risk of poor mental health. An internet-based mental health intervention could be a feasible and effective first step to improve students' mental health.