Reading literacy is regarded as one of the most crucial prerequisites for academic success in all fields. PISA surveys reading literacy with extensive demographic data in several countries to provide detailed feedback for detecting problems in their education systems. In many countries, bilingual students are facing several problems in schools, especially language-related problems. In this context, this study is causal-comparative research aiming to compare bilingual and monolingual students' Turkish reading literacies based on PISA 2018 data while controlling their economic, social and cultural status. In Turkey, 6890 students from 186 schools, who were selected through stratified random sampling, participated in PISA 2018 implementation. Bilingual and monolingual students' reading literacies were compared through ANCOVA where their economic social and cultural status is the covariate. Findings showed that monolingual students have greater reading literacy scores than bilingual students when their economic, social and cultural status were controlled. This finding indicates that there may be some problems in Turkish language teaching/learning strategies for bilingual students, which do not originate from their economic, social and cultural status. In this paper, the possible reasons for bilingual students' low reading literacy, are discussed, and some possible solutions for these problems are suggested.