In recent years, Tabriz has faced growing environmental challenges such as air pollution, incompatible land uses, poor waste management, and declining per capita green space, negatively affecting public health and ecological resilience. Institutional fragmentation, weak coordination among agencies, and sectoral policymaking are major barriers to effective environmental management. This study assessed the role of integrated urban management in improving environmental quality through a quantitative survey and structural equation modeling using SmartPLS. Data were purposively collected from 92 managers and experts, and measurement validity and reliability were confirmed. Results revealed that integrated urban management influences environmental quality indirectly through a sequential chain. Path coefficients were: integrated urban management → institutional cohesion (β = 0.48), institutional cohesion → environmental governance (β = 0.52), environmental governance → spatial justice (β = 0.45), and spatial justice → environmental quality (β = 0.50), all significant at p < 0.001. The coefficient of determination (R²) for environmental quality was 0.60, and Q² was 0.31, indicating good predictive power. The overall model fit (GOF = 0.58) confirmed adequacy. Strengthening institutional capacity, enhancing intersectoral coordination, and adopting spatial justice-oriented planning can significantly improve environmental quality in Tabriz. These findings provide a policy-relevant framework that can guide sustainable urban planning in other metropolitan areas with similar environmental challenges.