Background. Regular consumption of a well balanced breakfast is a pre-requisite for normal growth and child development, along with the acquisition of proper eating habits. The family environment is crucial place where children learn such patterns of behaviour that form the basis for their development. Objectives. To determine how family factors affect the regular eating of breakfast and types of foodstuffs consumed in primary school pupils, including food purchases made from vending machines and school tuck shops. Materials and methods. Subjects were 836 pupils (435 girls and 401 boys, aged 6 - 13) from Warsaw and the surrounding areas. Appropriate socio-demographic data and relevant eating habits were obtained from direct interviewing of the subjects by means of a custom designed... questionnaire. Statistical analyses were performed by the Kohonen type cluster analysis model and Chi-square test (Chi2); (p≤0.05). Results. Three clusters of pupils were identified by their differing socio-demographics and eating habits (eg. rates of breakfast consumption, buying from vending machines or school tuck shops). The first and third clusters were mainly pupils from two-parent families with parents proportionally spending similar times at work, where respective breakfast (87% and 91%) and second breakfast (77% and 72%) consumption rates were also similar together with food shopping rates during school time (respectively 69% and 63%). Pupils with single-parents, multi-generation families or if both parents were professionally active, predominated in the second cluster. These ate breakfast (73%) and second breakfast (67%) more rarely, but more frequently shopped for food at school (84%). A small number of pupils had a packed second breakfast from home, rarely ate sandwiches, fruit and/or vegetables and dairy products but ate more sweets, sweet rolls and savoury snacks. However, a large number of subjects bought sandwiches, fresh fruit and/or vegetables and fast-food at school. Conclusions. Family factors were found to affect eating habits in children and adolescents regarding how often breakfast was eaten and the type of foodstuffs consumed. High consumptions of unhealthy food items for second breakfast were also observed. Single-parent pupils, those in multi-generation families or if both parents are employed rarely brought second breakfasts from home but frequently bought food from vending machines and school tuck shops. The results of the presented findings are significant towards planning an appropriate educational campaigns and health programmes targeted at children, adolescents and their families.