Land use and transport integration (LUTI) has been promoted around the world as essential for sustainable urbanization. Using Seoul as a case study, this paper critically examines if and how LUTI policy can bring positive social outcomes, including accessibility and quality of life, in rapidly-growing megacities. We explored stakeholder views about the experience of these outcomes in different localities, and about critical elements and processes needed to enhance social outcomes. Our research identified that facilitating compact urban form around transport nodes does not guarantee increased accessibility or livelihood opportunities. The outcomes are closely related to the quality of development around nodes, accessibility to public facilities, local mobility, and functionality of pedestrian paths. Ensuring sustainability of social outcomes from LUTI approach requires: balancing restrictions and incentives to control quality of development around nodes; creating cost-effective strategies to maintain local environmental quality; applying flexible rules to address varying priorities and opportunities in different localities; and multi-level planning that balances the responsibilities of metropolitan and local stakeholders to facilitate desired outcomes. We conclude that, in rapidly-growing cities, a flexible and holistic approach to integration should be applied to reflect diverse needs and local circumstances and to ensure fair benefits across the city.