Philosophiae Doctor - PhD / The Health Promotion Model provides a theoretical framework exploring the relationships between healthy lifestyle behaviours of individuals. The three behavioral determinants affecting healthy lifestyle behaviours as posited by the model are (i) individual characteristics, (ii) behaviour-specific cognitions and affects, and (iii) behavioural outcomes that promote health. Research indicates that a number of health risk behaviours are established in adolescence and affect health and well-being in later life. In South Africa where young people account for more than 9 million of the population, and with adolescence being a period where the development of health risk behaviours is prevalent, it becomes important to research the associations that aid in healthy lifestyle behaviours of adolescence in this country, particularly in rural communities where research on adolescents remains limited. This study therefore aimed to develop and test a model that examined the effects of the interaction between perceived parenting styles and adolescent decision making styles on healthy lifestyle behaviours of adolescents in the rural Western Cape. The study employed a mixed methodological sequential exploratory design, using (i) systematic reviews and (ii) a quantitative methodology with a cross-sectional research design. Systematic reviews established the associations in existing empirical studies that examined the associations of parenting approaches with (a) healthy lifestyle behaviours and (b) decision making styles. Quantitative data was collected using a self-report questionnaire that consisted of four sections, demographical information, Parenting Style and Dimension Questionnaire, Health-Promoting Lifestyle Profile II and the Melbourne Decision Making Questionnaire among 457 Grade 9 learners in the Overberg Education District in the Western Cape, South Africa. The quantitative data was analysed using the Statistical Package for Social Sciences V23 (SPSS) for descriptive and inferential statistics (correlations and multivariate analysis of variance) and the Analysis of Moment Structures (AMOS) for confirmatory factor analysis and structural equation modelling. The systematic reviews suggested that empirical studies have found parenting approaches to be associated with (i) healthy lifestyle behaviours and (ii) decision making styles of children and adolescents in existing literature. The quantitative studies showed that perceived authoritative parenting, vigilant decision making styles, and frequent engagement in healthy lifestyle behaviours were the most prevalent among adolescents in the rural Western Cape. No significant main effects were established on the basis of participant gender or family structure. The model developed and tested, guided by the Health Promotion Model, suggests that a significant positive relationship exists between maternal parenting styles and decision making styles of adolescents. In addition, the findings demonstrated that paternal parenting styles positively affect the decision making styles of adolescents as well as their engagement in healthy lifestyle behaviours. Overall, the study suggested the important role that parents play in adolescent decision making styles and healthy lifestyle behaviours, and even more the role of paternal parental figures in the development of children and adolescents.