The impact of socio-economic status is a topic that has long been emerging in the field of education. Numerous scientific papers include the impact of socioeconomic status on student achievement in school among other factors. Socio-economic status (SES) encompasses not only parental income, but also education, financial security, and subjective perceptions of social status and social class. Socio-economic status can include the attributes of quality of life, as well as the opportunities and privileges provided to people in society. Poverty, in particular, is not an individual factor, but is characterized by multiple physical and psychosocial stressors. Furthermore, SES is a consistent and reliable predictor of a wide range of life expectancy outcomes, including physical and mental health. Therefore, SES is relevant to all areas of behavior and social sciences, including research, practice, and education. Given the current state of society and education in Croatia, it was important to take into account the socio-economic status as a factor that significantly affects the success of high school students. In this paper, a t-test for independent samples was conducted to examine the difference in school achievement depending on gender. Also, correlation coefficients of age, indicators of socioeconomic status and school success in boys and girls were calculated. The results showed that in young men there is a significant positive correlation between mother's education, father's education and assessment of material opportunities with average school success with a level of risk of less than 5%. The higher the education of the mother and father, the better the school success of the young men. In girls, a statistically significant positive association of mother and father education with average school achievement was found, with a risk level of less than 5%. The higher the education of the parents, the higher the average school success.