Until recently, emotions were considered a weakness and they were reserved only for the certain private occasions, also they differentiated across different cultures in a such a way that the same situation would provoke a different emotional reaction. When you add a business activity and business success, the situation gets even more complicated as it was general conception that emotions and business are incompatible, that emotion are the weight which disables rationality in the business decision making. The situation started to change after positive results emerged as a result of emotions, especially in the organizational leadership, which could not be explained with at the time known concepts. It occurred relatively late, in the last quarter of 20th century when concept of emotional intelligence was established. Therefore, the subject of this thesis is approximation of emotional intelligence concept and its main elements, its effect according to the age, sex and cultural differences, the characteristics of the emotional intelligent individuals and pointing out its significance for development of the modern organizations which stand out in terms of the human capital and excellence in the leadership when compared to organizations who are focused only on the technical skills. The empirical research was conducted on the employees of public administration with purpose of studying effect of emotional intelligence on business success. Research has shown the existence of casual relationship between higher hierarchy levels and higher levels of emotional intelligence which is consistent with objectives of this thesis. Above mentioned is excellent finding, although with sample limitations, which supports affirmation of emotional intelligence concept in Croatia. Therefore, it is useful for development of overall society competitiveness, both in private and business sense.