The theoretical part of the monograph presented theories and models of parent-child health-related behaviours, including parental involvement in the physical activity, screen time, and eating behaviours of their children. The findings of retrospective, experimental, and meta-analytic studies indicate that a long-term positive outcome for the reduction of the excessive body weight of children or the formation of an active lifestyle requires the active participation of parents. Therefore, the main objective of the monograph is to describe the parent-child patterns of the physical activity and sedentary behaviour of Czech families with pre-schoolers and school-aged children and answer the question of which family-based determinants affect the likelihood of the overweight/obesity of children.