This study analyzes the environmental consequences of urban development in Tehran over a 10‑year period (2014–2024). Using a descriptive‑analytical approach, secondary data from official sources were examined through trend analysis and Pearson correlation.

Key findings show a shift from horizontal to vertical development: building permits decreased by 42%, but the share of high‑rise buildings increased by 33% to 64%. Air quality improved slightly – clean days rose by 31% to 17 days – yet PM2.5 levels remain 3–4.5 times above global standards. Per capita green space increased by 15% to 6.8 m², but a 26‑fold disparity exists across districts (2.9–76.8 m²), revealing severe spatial inequality. Water consumption rose by 9% to 250 litres per day – twice the global average – and the mean annual temperature increased by 5%.

Correlation analysis confirms strong links between urban density and environmental degradation. The highest positive correlation was between population density and water consumption (0.71), while the strongest negative correlation was between building density and per capita green space (–0.67).

The study concludes that Tehran’s urban development has led to densification, worsening spatial inequalities, and persistent environmental crises. Recommendations include revising urban development plans, equitable distribution of environmental services, water resource management, expanding public transportation, and increasing green spaces in disadvantaged areas.