Mental health is related to depression, anxiety and stress, all of which affect the individual. Without good mental health, developing one's potential is difficult. Therefore, identifying the main factors affecting mental health is important to ensure the individual is capable of handling pressure and stress to accomplish given tasks well. Even though much research has been done to determine the factors that contribute to mental health, findings on the cause-effect relationship between the factors and mental health specific to engineering students is limited. Thus, this paper addresses the factors that are directly related to the mental health of students in technical universities in Malaysia. The survey research design was used in this study. The sample consisted of 379 students from three Malaysian technical universities (MTU), namely Universiti Tun Hussein Onn Malaysia (UTHM), University Technical Malaysia Melaka (UTeM) and Universiti Malaysia Perlis (UniMAP). The Depression, Anxiety and Stress Scale 21 (DASS-21) inventory and a questionnaire developed by the researchers were used to measure the students' mental health based on three elements (depression, anxiety and stress) and the factors affecting mental health (self-evaluation, living style, health, learning environment, parents, peers, lecturers, academic factors, financial factors and the lost). The data collected were analysed using frequency, percentage, mean and multiple linear regression. Based on the analysed data, a regression equation for the relationship between the various factors that contribute to mental health level was formulated. Counsellors and lecturers may use the developed formula as a reference when dealing with mental health issues affecting engineering and non-engineering students.