The present study aimed at recording Greek student teachers’ beliefs in relation to bilingualism and their views on linguistic and cognitive development of bilingual immigrant students who attend Greek primary schools. The sample consisted of 64 fourth year students of the Department of Primary Education of the University of Western Macedonia and Aristotle University of Thessaloniki. The basic research instrument was semi-structured interviews including open questions which were organized into the following thematic strands: a) defining bilingualism, b) factors affecting bilingualism, c) cognitive and linguistic development of bilingual students, d) differences between monolingual and bilingual students’ linguistic competence and cognitive/academic performance, e) educational/teaching methods and techniques. The data were analyzed qualitatively based on: a) the Miles and Huberman framework of analysis; b) the Fairclough’s critical discourse analysis. The findings of the study revealed student-teachers’ misconceptions about certain issues concerning bilingualism and academic and linguistic performance.