Rapid urban growth and uncontrolled expansion, especially in developing countries like Iran, challenge urban planning. This study aims to develop a sustainable urban density model based on an urban ecology approach, integrating governance, environmental sustainability, and spatial efficiency, with a case study in District 2 of Tehran Municipality. This applied-developmental study employs an analytical modeling approach. Data collection was carried out through documentary research and expert questionnaires. Confirmatory Factor Analysis (CFA) using SPSS was used to validate the relationships between environmental factors and urban density. Reliability and validity were assessed through Cronbach’s alpha and the Kaiser-Meyer-Olkin (KMO) measure. A structural model was then developed to illustrate the key environmental influences on urban density. Key factors such as green space per capita, land-use patterns, and the built environment influence urban density distribution. The findings underscore the importance of integrating ecological principles into urban planning. The proposed model provides practical recommendations for enhancing environmental resilience and sustainable growth. The study highlights the need for smart density strategies and optimizing land-use efficiency to mitigate urban densification’s negative effects. The Urban Density Model offers a framework for policymakers to promote environmental  quality and sustainable urban development.