The main drive for this study is to look into potential predictors of educational achievement using OECD's original Pisa 2018 dataset. This paper explores (i) access to ICT, (ii) physical characteristics of learning environment at school, (iii) quality of teaching staff and educational material, (iv) student characteristics and learning climate, and (v) political and economic structure of the country as potential true predictors of academic achievement. Our sample covers 41 countries and data used in our analysis are collected from 282,461 students distributed in 9,317 schools worldwide. Multiple linear regressions are developed and analyzed using stepwise estimation techniques. The results indicate that (i) availability of internet connection and enjoyable pastime activity at home have positive impacts on student's success, (ii) a strong correlation exists between high test scores and student characteristics & learning climate, i.e. students' sense of belonging at school, students' fear of failure and disciplinary climate, (iii) there is a negative relationship between academic performance and teacher enthusiasm & support, (iv) student success is negatively correlated with income level and political and economic freedoms but positively associated with economic competitiveness of a country, and (v) the students in lightly populated classes are more successful than those in overloaded ones and inadequate or poor educational material deteriorates educational outcomes.