The aim of this dissertation is threefold. First, to study the factors that are associated with parenting self-efficacy and parenting stress. Second, to study factors that are associated with child health and wellbeing, namely sleep problems and problem behavior. And third, to describe the design of a study to evaluate the effects of parenting support on parenting and parents’ and children’s health and well-being in a ‘real-world’ setting. For this purpose, the following research questions were formulated: Part one: Factors associated with parenting stress and parenting self-efficacy • What parental, child, and socio-contextual factors are associated with general parenting stress among parents with children aged 0-12 years in the general population? (Chapter 2) • What parental, child, and socio-contextual factors are associated with general parenting self-efficacy among parents with children aged 0-18 years in the general population? (Chapter 3) • What parental, child, and socio-contextual factors are associated with parenting self-efficacy among parents of children aged 0-7 years old in the general population? (Chapter 4) Part two: Factors associated with child health and wellbeing • What parent, child and family factors are associated with sleep problems among children aged 0-8 years old? (Chapter 5) • What is the association between stressful life events and emotional and behavioral problems in children aged 0-7 years old? (Chapter 6) Part three: Evaluation of parenting support • What is the study design to evaluate the effects of the use of parenting support regarding the intended ‘outcomes’ on parenting (i.e. parenting style, parenting daily parenting stress, and parenting sense of competence ) and the health and well-being of parents (i.e., parental psychological distress) and children (i.e., problem behaviors) in a ‘real-world’ setting? (Chapter 7) Chapter 2 and 3 are systematic reviews and include an overview of studies identified from the databases PubMed, ScienceDirect, Web of science and/or Embase. Chapter 4, 5, and 6 use data of the CIKEO project, a community-based naturalistic study, which aimed to investigate the use of parenting support interventions in the daily practice of Dutch preventive youth health care. The first part of the dissertation focused on factors associated with parenting stress and parenting self-efficacy. Chapter 2 summarized existing observational studies on a wide range of parent, child, and contextual factors associated with parenting stress among parents of children aged 0-12 years old. There was evidence of an association between maternal depression, child overall problems, externalizing and internalizing behaviour problems, social support, maternal educational level and maternal parenting stress. There was evidence for an association between child sex and paternal parenting stress. Evidence was inconsistent for an association between maternal anxiety, family income and maternal parenting stress. There was no evidence of an association for maternal age, child sex, and maternal parenting stress. Chapter 3 synthesized the literature on the parental, child, and socio-contextual factors related to general parenting self-efficacy among parents with children aged 0-18 years in the general population. There was evidence of associations between child temperament, maternal parenting satisfaction, parenting stress, maternal depression, household income, perceived social support and parenting self-efficacy. Evidence was inconsistent for an association of educational level, parity, number of children in the household and parenting self-efficacy in mothers. There was no evidence of an association for child gender, age, marital status and parenting self-efficacy in both mothers and fathers; ethnicity, age, employment status in mothers; household income in fathers; and educational level, parenting fatigue in parents. In Chapter 4, we assessed factors associated with parenting self-efficacy in parents of children aged 0–7 years old. In addition, the association was studied for the subgroup of mothers and the subgroup of fathers. Associations were observed between several parental (i.e., parenting stress, general health status, migration background), child (i.e., eating and behaviour problems, general health status) and social-contextual factors (i.e., number of children, perceived social support) and parenting self-efficacy. A potential difference between mothers and fathers was observed regarding the association between family functioning and parenting self-efficacy. Better family functioning was statistically significantly associated with higher parenting self-efficacy in the subgroup of mothers; this association was not observed in the subgroup of fathers. The second part of the dissertation focused on factors associated with child health and wellbeing. In Chapter 5, the prevalence and the development (incidence and persistence) of sleep problems, indicated by extended sleep latency and frequent night awakening, was investigated. The prevalence of sleep problems among children aged 0-8 years old was 13.3% at baseline and 15.4% at follow up, respectively. The incidence and persistence rates of sleep problems in children at follow up were 12.0% and 37.6%, respectively. Being a girl, having a chronic condition, experiencing stressful life events, and having lower parenting self-efficacy at baseline was associated with a higher risk of having a sleep problem at follow up. A higher level of parental psychological distress was associated with the persistence of sleep problems in children. Chapter 6 described the association between stressful life events and emotional and behavioral problems in children. A dose-response association with children exposed to a higher number of stressful life events having higher parent-reported total, externalizing and internalizing problem scores was found. The impact of an individual stressful life event was explored (e.g., the experience of divorce). Specifically, individual stressful life events ‘work-family spillover’ and ‘conflicts with neighbors, friends, acquaintances or family’ were associated with more total, externalizing and internalizing behavior problems. Some events, namely, ‘financial problems’, ‘problems in the marriage’ and ‘divorce’ were associated only with more internalizing problems. The last part of the dissertation focused on parenting support interventions and parents’ and children’s health and wellbeing. Chapter 7 described a study design to evaluate the effects of the use of parenting support on parenting (i.e. parenting style, parenting daily parenting stress, and parenting sense of competence) and the health and well-being of parents (i.e., parental psychological distress) and children (i.e., problem behaviors) in a ‘real-world’ setting. This is part of the CIKEO consortium study (Consortium Integration Knowledge promotion Effectiveness Of parenting interventions). The overarching aim of the CIKEO consortium is to investigate preventive parenting interventions, in order to identify effective elements within these interventions. Finally, Chapter 8 provided an overall discussion, including a description and interpretation of the main findings of the dissertation, methodological considerations, directions for future studies, as well as implications for policy and practice. The findings of this dissertation provide directions for future research and implications for policy and practice. The following suggestion were made with regard to future research: 1) include a diverse study population and continue to include a representative sample of fathers as well as other caregivers; 2) further explore the interplay of the parent, child and contextual factors with regard to parenting, parents’ and children’s health and wellbeing; 3) and to further explore the effects of parenting supporting interventions in a ‘real-world’ setting. In summary, our findings indicate that parenting and the health and well-being of parents and children are affected by multiple factors in the parent, child and contextual domain. A joint effort between parents, families, schools, the community, public health professionals, and the policymakers is needed to promote optimal parenting, parents’ and children’s health and wellbeing.