This thesis focuses on the influence of emotional intelligence in the secondary age children and how it affects their school performance. Emotional intelligence as a kind of intelligence that began intensive study back the past twenty years has attract many scientists, even to the extent that some claim is more important than IQ. Emotionally intelligent people are better able to recognize their own and other people's feelings and direct them towards achieving a specific objective. In addition, they possess a higher degree of empathy and motivation and foster better relationships. For these claims rests assumption that such people are successful in business and life. The thesis is addressed to these assumptions, first through the theoretical framework, and then through the reflection of the relationship between IQ and emotional intelligence quotient. After that, there is an overview of the opinions on the importance of both the quotient and the possibilities for their increase. After the theoretical part, emphasis is placed on a specific topic, and that is the importance of emotional intelligence in education. In secondary education emphasis is placed on cognitive abilities and their development, while feelings are almost completely ignored. The assumption on which research is based is that emotionally intelligent students achieve better grades in school. Except that, it is assumed that whole school system would benefit from the increase of EQ. However, research has not confirmed connection between these two variables, but there are findings that successful students are more motivated and have better social skills.