PhD (Public Health) / Department of Public Health / The well-being of adolescents’ population is a major concern to policy makers, educators and researchers all over the world. Research has shown that adolescents engage in deviant and risky sexual behaviour, and such behaviour may have consequences for their present or future health. Likewise, it has been shown that adolescents are also known to conform to societal norms if they are given proper guidance. In the light of this, the present study proposed to explore and explain the influence of family dynamics in the occurrence of adolescents deviant and sexual risk behaviour. This study involved a sequential explorative, descriptive and analytic mixed method design, combining both qualitative and quantitative research approaches. The study was divided into three (3) phases. Phase 1 was purely qualitative in nature, where a total of 10 parents and 13 adolescents were engaged in an in-depth interview. Phase 2 was quantitative in nature, using a cross-sectional analytic design involving 388 adolescents, while Phase 3 was the development of a public health intervention to mitigate the influence of family dynamics on adolescent deviant and sexual risk behaviour. The qualitative data were analysed using thematic content analysis, while the quantitative data were analysed using the Statistical Package for Social Sciences (SPSS) version 22. The Chi-square test, Fisher’s exact test, multinomial and binary logistic regression were used to compare differences between the dependent and independent variables. The level of statistical difference was set at p<0.05. Couple conflicts was a common finding in the study. In addition, many families suffered severe financial constraints and some parents were disconnected from their children physically, emotionally and financially (particularly the fathers). Adolescents claim that the age difference between them and their parents remains a barrier to communication, in addition, some participants claimed that they received little or no sex education from their parents. The present study found a high level of recent physical violence (30%), alcohol (52.9%) and drug use (10%) among participants. The level of sexual activity in this study was high, with 60.1% of the participants being sexually active and 23.1% having been pregnant. In addition, only 35.6% using condoms regularly. There was gender difference among participants on the following variables: cigarette smoking, teenage pregnancy and having multiple sexual partners. Furthermore, participants differed significantly across age group on the following variables: cigarette smoking, sexual activity, having friends who are sexually active, reported pregnancy and currently having iii a relationship. However, ‘relationship with mother’ was the family dynamic variable that recorded a wider effect on deviant and sexual risk behaviour. Furthermore, age, duration of stay in the community, living with siblings, relationship with mother, having enough money at home, being supported emotionally at home and parental love for each other, were predictors of deviant and sexual risk behaviour in the present study. There was also low level of risk perception and low level of skill for self-protection among the participants. As part of the objectives of the present study, the study findings were used to develop an evidence-based public health programme targeted at vulnerable adolescents and adolescents at high risk for deviant and sexual risk behaviour. It is hoped that this programme will be able to empower parents and caregivers to apply better parenting practices to forestall undue exposure of adolescents to factors that contribute to deviant and sexual risk behaviour. The present study demonstrated that although adolescents have the propensity for deviant behaviours, many may transit to adulthood without much adverse sequelae even in the face of harsh family social and economic adversities. However, a proportion of the adolescent population in this community remains vulnerable due to the effects of family de-structuring, poverty and unemployment. / NRF