PhDPH / Department of Public Health / Substance use/abuse is a persistent public health problem in tertiary institutions around South Africa. Alcohol and illegal drugs are the most commonly-used substances by youths in tertiary institutions, including student nurses at the Limpopo College of Nursing (LCN). This study sought to develop a model to prevent substance use/abuse by student nurses at the LCN, South Africa. A convergent parallel mixed-method was used to collect and interpret the data. A phenomenological research approach was utilized for gathering data from the lecturers, student affairs officers and student nurses in the qualitative design which was explorative and descriptive in nature. The population comprised of student nurses, lecturers and student affairs officials who were purposefully selected. Data were collected through unstructured in-depth interviews and analyzed through Tesch’s open-coding steps for qualitative empirical research to develop themes and categories. Data generated the following themes: The Consequences of Socialization Factors on the Incidence of Substance Use/Abuse by Student Nurses and The Effect of Environmental Factors on the Incidence of Substance Use/Abuse by Student Nurses. Within each theme, sub-themes emerged. Trustworthiness of the collected data were ensured. A quantitative design was employed to collect data from all student nurses in five campuses of LCN. A stratified sampling technique was used to select respondents and structured questionnaires were used to collect data. A total of 445 questionnaires were collected. Quantitative data were analyzed numerically and through descriptive and correlation statistics using the Statistical Package for the Social Sciences (SPSS) version 24. The results showed that substance use/abuse is more prevalent among students of the age group of between 21 and 24 years that represented the majority in LCN. Data were analyzed independently for which a convergent analytic approach was used to merge the data sets. Validity and reliability were ensured. Ethical considerations were adhered to. The overall findings highlighted that substance use/abuse by the student nurses was widespread. Various factors, including behavioural, environmental and student earning stipend, have contributed to the problem. The concept “prevention” was analyzed using Walker & Avant’s (2014) steps. The results of both the empirical study and concept analysis formed the basis for model development. The framework of Dickoff, James and Wiedenbach (1963) was used to develop a model. The developed model was validated by the group using a close-ended checklist, analyzed using simple descriptive statistics. The model was in accordance with the legislative provisions of the LCN lease agreement, Higher Education Act as well as the National Institute on Drug Abuse (NIDA, 2003). / NRF