The aim of this thesis was to examine the contribution of subjective well-being, self-esteem, optimism and pessimism to the explanation of school success in students from upper grades of elementary school. Participants were 103 students from upper grades of two elementary schools in Virovitica. The following questionnaires were used: Students’ Life Satisfaction Scale, SLSS (Huebner, 1991b), Rosenberg Self-Esteem Scale (Rosenberg, Schooler i Schoenbach, 1989), The Youth Life Orientation Test (Ey et al., 2005) and PANAS Questionnaire (Watson, Clark i Tellegen, 1988). The results showed that students with a higher grade point average have less pronounced pessimism, are more satisfied with life and have higher self-esteem. Students who have more pronounced optimism, have less pronounced pessimism, feel less negative affect and more positive affect, are more satisfied with life and have higher self-esteem. Students who have more pronounced pessimism are less satisfied with their lives, have lower self-esteem, experience less positive affect and more negative affect. Students who are more satisfied with their life have higher self-esteem, more postitive affect and less negative affect. Students who experience more positive affect are less likely to experience negative affect. The grade point average is not statistically significantly associated with positive and negative affect and with optimism. The regression model was statistically significant and this set of predictors, i.e. life satisfaction, positive and negative affects, self-esteem, optimism and pessimism explained 17.57% of the variance of the criteria, grade point average. Only the construct of life satisfaction had an indipendent contribution in explaining the variance of grade point average. Life satisfaction is positively related to the grade point average, i.e. the more satisfied students are with their life, the higher the grade point average.