The purpose of this study was to explore mathematics teachers' perception of social justice in mathematics classrooms. We applied interpretive qualitative method for data collection, analysis, and interpretation through iterative process. We administered in-depth semi-structured interviews to capture the perceptions of three mathematics teachers about social justice in mathematics classroom at three public secondary schools in Kathmandu. We carried out multiple layers of thematic analysis and interpretation of the narratives from the interview data. Altogether five themes on perception of social justice emerged from the analysis of the data. These themes were associated with - equality, equity, fairness, social process, and caring students. Implications of the study have been discussed at the end.