School success is an important factor in the life of every individual because many aspects of the individual's life depend on it: further education, choice of future occupation, quality of life, even personal satisfaction and happiness. Even though school success is not easy to define, it is important to understand that it includes successfully mastering the materials, acquiring the necessary skills and habits, and adapting to the social environment. Today, however, school success is mostly attributed to grades that have become imperative in society, while neglecting the student’s actual abilities and skills. It is on the basis of school success that students create an image of themselves, as well as try to fit into the society. Numerous researchers have studied various factors that affect school success and singled out family as one of the most important. Family structure, the quality of family and school partnerships, and level of parents' educations proved to be important factors of school success as well as a harmonious family relationship. Many studies showed that family has a strong impact on the child’s school success, mental development and life satisfaction. The aim of this research was to examine the connection between parental education and school success of students, and their life satisfaction and level of happiness at the end of lower primary and upper primary school. The research was conducted on a sample of 195 fourth and eighth grade students, that is 93 fourth grade students and 102 eighth grade students from public schools in the city of Sisak. The results showed that children whose parents have a higher level of education achieved better school success regardless of the sex of the child. When it comes to well-being, there is no difference in the life satisfaction of children whose parents have a higher or lower level of education. The results also showed that students' school success is above average in general, as well as their life satisfaction and happiness.