Purpose: The purpose of the study is to investigate the socioeconomic and sociocultural factors that affect the success of the PISA 2018 Turkey sample in the fields of mathematical literacy, science literacy and reading skills in terms of the indexes created by PISA. Methodology: The sample of the study consists of 6890 students. In PISA 2018, the average of ten plausible values created for each student was taken and student achievement scores were obtained. Stepwise Regression Analysis was applied to determine the extent to which the indexes predict student achievement. Findings: The most predictive variables are Economic, Social and Cultural Status Index, occupational status of parents and Cultural Possessions Index. Information and Communication Technology Index negatively affects the achievement. Highlights: Non-formal education should be used to increase the education level of students’ parents. In order to reduce the inequality of opportunity for students whose families have a low socioeconomic level, the opportunities offered to schools in disadvantaged regions should be increased. Parents should be educated on the use of information and communication technology at home.