Environmental (in)justice research uses various conceptual frameworks and methodological approaches, leading to fragmentation across contexts and disciplines. Our systematic review provides a methodological overview of how environmental (in)justice has been studied in 421 English-language scientific articles. Most studies approach environmental (in)justice from a quantitative and interdisciplinary perspective, primarily using purposive sampling, secondary data, and GIS/remote sensing tools with an emphasis on distributive justice. Although there is a notable diversification over time in data collection and analysis, there is a strong geographic bias with short-term, locally focused, and limited actor involvement, though actor diversity is growing over time. We identified eight thematic clusters with distinct methodological patterns: health, pollution, governance, climate change, collaboration, access, and green space. The lack of broadly adopted methodological approaches for evaluating environmental (in)justices largely stems from the context-specific, multi-scalar nature of cases and the philosophical and normative diversity embedded in the EJ concept itself.